Question:
I have a 20 X 40 in ground swimming pool. I would like to install solar collectors to heat it. I do not particularly like the Idea of 400 or more square feet of solar collectors on my roof (faces south no shade) not to mention the $$$$. I was wondering if anyone has any info on a homemade collector suitable for this type of system that would use less real-estate on my roof. My questions really boil down to: 1) Can I make a more efficient system myself for less money than those plastic panels? 2) If I make it more efficient can I get by with less square footage? My initial idea is to run several lengths of 1/2" copper pipe between two 2” copper headers all fastened to a 3 X 10 corrugated metal roofing panel maybe even boxed in and glazed if that will help. I cant see this costing more than about $100 dollars a panel. This is our second year in this house and I don’t want to pay the same gas bill I did last year. ouch!! Thanks David.
Response:
> I have a 20 X 40 in ground swimming pool. I would like to install solar > collectors to heat it. I do not particularly like the Idea of 400 or more > square feet of solar collectors on my roof (faces south no shade) not to > mention the $$$$. I was wondering if anyone has any info on a homemade > collector suitable for this type of system that would use less real-estate > on my roof.
Perhaps you sould look for some panels that don’t offend your eyes so much. You have a good roof for it, might as well make the maximum use, rather than trying to minimize the area of something you find ugly.
Response:
Too complicated for water that is going to be chlorinated anyway. Your roof will not leak water right. Your roof gets hot during the daytime right Your roof has eves and down-spouts right. Maybe not if you live down south Run your filter outlet to the top of the roof and let it squirt out through holes in a header pipe that runs along the peak. Collect the now warmer water in eves and run it through a filter to keep the dirt out. Need to have a diverted valve for when it rains or live with a really full pool. My parents do this and it works fine. They haven’t bought water for the pool in 20 years. Bill Roosa
– Hide quoted text — Show quoted text -> I have a 20 X 40 in ground swimming pool. I would like to install solar > collectors to heat it. I do not particularly like the Idea of 400 or more > square feet of solar collectors on my roof (faces south no shade) not to > mention the $$$$. I was wondering if anyone has any info on a homemade > collector suitable for this type of system that would use less real-estate > on my roof. > Perhaps you sould look for some panels that don’t offend your eyes so > much. You have a good roof for it, might as well make the maximum use, > rather than trying to minimize the area of something you find ugly.
Response:
> Too complicated for water that is going to be chlorinated anyway. > Your roof will not leak water right. > Your roof gets hot during the daytime right > Your roof has eves and down-spouts right. Maybe not if you live down south > Run your filter outlet to the top of the roof and let it squirt out through > holes in a header pipe that runs along the peak. Collect the now warmer > water in eves and run it through a filter to keep the dirt out. > Need to have a diverted valve for when it rains or live with a really full > pool. My parents do this and it works fine. They haven’t bought water for > the pool in 20 years. > Bill Roosa
I’m all for inovation (especially cheap low tech) but let’s pose a few questions. What kind of roof(s) are we talking about? I’ve seen leaking pool panels rot out galvanized drip edge, roofing nails,and valley. I don’t think copper would fare much better when exposed to this caustic substance. Evaporation could be a problem. It is prolific enough from the surface of a heated pool. Maybe 2nd hand corrogated panels with UV tolerant plastic draped over it dumping the pool water directly into the gutter? A clear plastic (UV tolerant)cover over the both would hold down evaporation. Windload would be a consideration with this apparatus however. If you put the black plastic directly on the roof then rot may occur. This idea has been expressed by Nick. Good, but needs tweaking to solve some potential problems. How about sheet aluminum on PT slats to keep it above the roof and allow "roof breathing"? Paint it black, even, or use the bronze baked stuff. One could deform the aluminum so it droops between the slat attachments and doesn’t rot the screws going through them and into the roof. Evaporation would still be a concern but at least the roof is left dry. Aesthetics is another matter. A green wallet is aesthetically pleasing to me. Dave – Hide quoted text — Show quoted text -> Perhaps you sould look for some panels that don’t offend your eyes so > much. You have a good roof for it, might as well make the maximum use, > rather than trying to minimize the area of something you find ugly.
Response:
>> Run your filter outlet to the top of the roof and let it squirt out > through holes in a header pipe that runs along the peak. Collect > the now warmer water in eves and run it through a filter to keep > the dirt out… My parents do this and it works fine… >What kind of roof(s) are we talking about?
Asphalt shingles? >I’ve seen leaking pool panels rot out galvanized drip edge, roofing >nails,and valley. I don’t think copper would fare much better when >exposed to this caustic substance.
How about covering the roof with a layer of EPDM rubber with a layer of fiberglass window screen above that to help the water spread out vs trickle in rivulets over the surface? >Evaporation could be a problem. It is prolific enough from the surface >of a heated pool.
Over 4×4 sleepers on 4′ centers, with clear polycarbonate over that? The materials might cost $3/ft^2 (30 cents/ft^2 for EPDM plus 50 cents for the window screen plus $1.50 for the polycarbonate, plus the 4×4s and ridge pipe), but it would probably last a lot longer than plastic pool heaters. You could also use it for solar heating and AC, a la Thomason, using a 2:1 CaCl2/LiCl solution… >If you put the black plastic directly on the roof then rot may occur.
That might be a problem if the plastic leaks or the underside of the roof is underventilated, with a poor vapor barrier in the attic floor, but those situations seem avoidable… Nick
Response:
Reduce the amount of collector by KEEPING the heat after you collect it. A solar pool cover! – Hide quoted text — Show quoted text – >I have a 20 X 40 in ground swimming pool. I would like to install solar >collectors to heat it. I do not particularly like the Idea of 400 or more >square feet of solar collectors on my roof (faces south no shade) not to >mention the $$$$. I was wondering if anyone has any info on a homemade >collector suitable for this type of system that would use less real-estate >on my roof. >My questions really boil down to: >1) Can I make a more efficient system myself for less money than those >plastic panels? >2) If I make it more efficient can I get by with less square footage? >My initial idea is to run several lengths of 1/2" copper pipe between two >2” copper headers all fastened to a 3 X 10 corrugated metal roofing panel >maybe even boxed in and glazed if that will help. I cant see this costing >more than about $100 dollars a panel. >This is our second year in this house and I don’t want to pay the same gas >bill I did last year. ouch!! >Thanks >David.
Response:
- Hide quoted text — Show quoted text ->> Run your filter outlet to the top of the roof and let it squirt out >> through holes in a header pipe that runs along the peak. Collect >> the now warmer water in eves and run it through a filter to keep >> the dirt out… My parents do this and it works fine… >What kind of roof(s) are we talking about? > Asphalt shingles? >I’ve seen leaking pool panels rot out galvanized drip edge, roofing >nails,and valley. I don’t think copper would fare much better when >exposed to this caustic substance. > How about covering the roof with a layer of EPDM rubber with a layer > of fiberglass window screen above that to help the water spread out vs > trickle in rivulets over the surface? >Evaporation could be a problem. It is prolific enough from the surface >of a heated pool. > Over 4×4 sleepers on 4′ centers, with clear polycarbonate over that? > The materials might cost $3/ft^2 (30 cents/ft^2 for EPDM plus 50 cents > for the window screen plus $1.50 for the polycarbonate, plus the 4×4s > and ridge pipe), but it would probably last a lot longer than plastic > pool heaters. You could also use it for solar heating and AC, a la > Thomason, using a 2:1 CaCl2/LiCl solution… >If you put the black plastic directly on the roof then rot may occur. > That might be a problem if the plastic leaks or the underside of the > roof is underventilated, with a poor vapor barrier in the attic floor, > but those situations seem avoidable… > Nick
Our resident genius at play (Nick Pine). I like this application for EPDM, too. I think there is still a possibility of roof rot if applying anything over, say, an asphalt (fiberglass shingle) roof. It mainly would occur if water was able to sneak in between the shingles and (in the updated case) EPDM. High humidity areas may have additional problems. I can’t stress this enough because the goal is inexpensive methods of heating water (for whatever purpose) and destroying a roof prematurely is counterproductive. If one was to re-roof (over a given area) using EPDM vulcanized onto the tin tagged felt then this would be a good approach in my view. One might substitute plastic wood 1×2(using stainless screws) for PT as the latter will eventually warp and/or rot. Lay the screen down and 1x directly on it. A bead of polyurethene caulk will futher discourage roof leakage where the screws penetrate (EPDM is supposed to be self sealing, but…) Tack on new greenhouse plastic every few years as a replacement item or after a hurricane/windstorm. That would be cheap enough. I think this one’s a runner. Anyone care to try it? Maybe try it on a large shed or even a tilted ground mount if they’re concerned about being a guinea pig. Dave
Response:
Is it the general consensus that pool water rots asphalt?! I have seen no evidence of this and can’t for the life of me figure out why chlorinated water would "rot" an asphalt roof. As for evaporation, if you limit the amount of roof that you use, and "flood" it during the collection period the temp rise is kept quite low and evaporation is acceptable. This is great as most of us don’t want to swim in 100F water anyway. Course you are using the whole roof to refill during rainy times so I’ve not seen this to be a problem either. Bill Roosa "a man with an experience is never at the mercy of a man with a theory" Author unknown
– Hide quoted text — Show quoted text -> >> Run your filter outlet to the top of the roof and let it squirt out > >> through holes in a header pipe that runs along the peak. Collect > >> the now warmer water in eves and run it through a filter to keep > >> the dirt out… My parents do this and it works fine… > >What kind of roof(s) are we talking about? > Asphalt shingles? > >I’ve seen leaking pool panels rot out galvanized drip edge, roofing > >nails,and valley. I don’t think copper would fare much better when > >exposed to this caustic substance. > How about covering the roof with a layer of EPDM rubber with a layer > of fiberglass window screen above that to help the water spread out vs > trickle in rivulets over the surface? > >Evaporation could be a problem. It is prolific enough from the surface > >of a heated pool. > Over 4×4 sleepers on 4′ centers, with clear polycarbonate over that? > The materials might cost $3/ft^2 (30 cents/ft^2 for EPDM plus 50 cents > for the window screen plus $1.50 for the polycarbonate, plus the 4×4s > and ridge pipe), but it would probably last a lot longer than plastic > pool heaters. You could also use it for solar heating and AC, a la > Thomason, using a 2:1 CaCl2/LiCl solution… > >If you put the black plastic directly on the roof then rot may occur. > That might be a problem if the plastic leaks or the underside of the > roof is underventilated, with a poor vapor barrier in the attic floor, > but those situations seem avoidable… > Nick > Our resident genius at play (Nick Pine). I like this application for > EPDM, too. I think there is still a possibility of roof rot if > applying anything over, say, an asphalt (fiberglass shingle) roof. It > mainly would occur if water was able to sneak in between the shingles > and (in the updated case) EPDM. High humidity areas may have > additional problems. I can’t stress this enough because the goal is > inexpensive methods of heating water (for whatever purpose) and > destroying a roof prematurely is counterproductive. If one was to > re-roof (over a given area) using EPDM vulcanized onto the tin tagged > felt then this would be a good approach in my view. One might > substitute plastic wood 1×2(using stainless screws) for PT as the > latter will eventually warp and/or rot. Lay the screen down and 1x > directly on it. A bead of polyurethene caulk will futher discourage > roof leakage where the screws penetrate (EPDM is supposed to be self > sealing, but…) Tack on new greenhouse plastic every few years as a > replacement item or after a hurricane/windstorm. That would be cheap > enough. I think this one’s a runner. Anyone care to try it? Maybe try > it on a large shed or even a tilted ground mount if they’re concerned > about being a guinea pig. > Dave
Response:
>> How about covering the roof with a layer of EPDM rubber with a layer > of fiberglass window screen above that to help the water spread out vs > trickle in rivulets over the surface?
The screen may not be needed if a deposit of minerals roughens the EPDM. > >Evaporation could be a problem… > Over 4×4 sleepers on 4′ centers, with clear polycarbonate over that? >…I like this application for EPDM, too.
It would go over the sleepers, so the screwholes would be 4" above the roof surface… >I think there is still a possibility of roof rot if applying anything over, >say, an asphalt (fiberglass shingle) roof. It mainly would occur if water >was able to sneak in between the shingles and (in the updated case) EPDM.
Very avoidable, IMO. Nick
Response:
> Is it the general consensus that pool water rots asphalt?! > I have seen no evidence of this and can’t for the life of me figure out why > chlorinated water would "rot" an asphalt roof.
Shingles, no. Galvanized drip edge, valley, roofing nails? Absolutely. > As for evaporation, if you limit the amount of roof that you use, and > "flood" it during the collection period the temp rise is kept quite low and > evaporation is acceptable. This is great as most of us don’t want to swim > in 100F water anyway. Course you are using the whole roof to refill during > rainy times so I’ve not seen this to be a problem either.
Evaporation will occur. The warmer the water, the more the evaporation. If you are in an area that is "regular as rain, fine. This is a lesser problem of the two. The basic principle of avoiding commercial collectors is sound and worth further experimentation. *Seeing is believing- Dave – Hide quoted text — Show quoted text -> Bill Roosa > "a man with an experience is never at the mercy of a man with a theory" > Author unknown
Response:
> >> How about covering the roof with a layer of EPDM rubber with a layer >> of fiberglass window screen above that to help the water spread out vs >> trickle in rivulets over the surface? > The screen may not be needed if a deposit of minerals roughens the EPDM.
Deposit of minerals roughens the EPDM? Do you mean a glazing of dried chlorine on the rubber? That would be a possibility. I would think it would reflect light? Maybe there wouldn’t be a deposit. Have you abandoned the screen idea? That may trap and deposit dried chlorine. >> >Evaporation could be a problem… >> Over 4×4 sleepers on 4′ centers, with clear polycarbonate over that?
No, only the unglazed version would evaporate. >…I like this application for EPDM, too. > It would go over the sleepers, so the screwholes would be 4" above > the roof surface…
At the surface where the 4×4 (or whatever size sleeper) meets the EPDM chlorinated water would potentually ooze under the sleeper and rust/rot a non stainless lag bolt and/ or the PT wood. Why a 4×4? Why not a shallower airspace? >I think there is still a possibility of roof rot if applying anything over, >say, an asphalt (fiberglass shingle) roof. It mainly would occur if water >was able to sneak in between the shingles and (in the updated case) EPDM. > Very avoidable, IMO. > Nick
Between the shingles and the EPDM. Trapped moisture promotes rot. Avoidable, yes. Dave
Response:
>> >> How about covering the roof with a layer of EPDM rubber with a layer > >> of fiberglass window screen above that to help the water spread out vs > >> trickle in rivulets over the surface? > The screen may not be needed if a deposit of minerals roughens the EPDM. >Deposit of minerals roughens the EPDM?
Maybe. >Do you mean a glazing of dried chlorine on the rubber?
I was thinking of calcium or magnesium. >I would think it would reflect light?
Bad news. We might dissolve it with acid once in a while. > >…I like this application for EPDM, too. > It would go over the sleepers, so the screwholes would be 4" above > the roof surface… >At the surface where the 4×4 (or whatever size sleeper) meets the EPDM >chlorinated water would potentually ooze under the sleeper and >rust/rot a non stainless lag bolt and/ or the PT wood.
I’d screw the sleepers to the roof, over the asphalt shingles, then lay the EPDM over the sleepers and roof, with a fold where the sleeper meets the roof, then screw the polycarbonate through the EPDM into the sleepers. >Why a 4×4? Why not a shallower airspace?
The polycarbonate might sag, and we might want enough space for natural airflow to remove water vapor from LiCl… Nick
Response:
> Is it the general consensus that pool water rots asphalt?! > I have seen no evidence of this and can’t for the life of me figure out why > chlorinated water would "rot" an asphalt roof. > Shingles, no. Galvanized drip edge, valley, roofing nails? Absolutely.
Well if your shingle roof was installed right, there should not be any exposed roofing nails and the galvanized drip edge "should" be installed under a shingle and painted to prevent rusting. Bill – Hide quoted text — Show quoted text -> As for evaporation, if you limit the amount of roof that you use, and > "flood" it during the collection period the temp rise is kept quite low and > evaporation is acceptable. This is great as most of us don’t want to swim > in 100F water anyway. Course you are using the whole roof to refill during > rainy times so I’ve not seen this to be a problem either. > Evaporation will occur. The warmer the water, the more the > evaporation. > If you are in an area that is "regular as rain, fine. This is a lesser > problem of the two. The basic principle of avoiding commercial > collectors is sound and worth further experimentation. > *Seeing is believing- > Dave > Bill Roosa > "a man with an experience is never at the mercy of a man with a theory" > Author unknown
Response:
Hi Bill, If the shingle stay saturated with water then any chlorinated water that reaches the core of the "asphalt shingle" would be in contact with the rag core, yes rags. GAF shingles utilize old cloth as the central core of the shingle so the fibers might be destroyed if saturated with chlorine on a regular basis. Offgridman – Hide quoted text — Show quoted text – > Is it the general consensus that pool water rots asphalt?! > I have seen no evidence of this and can’t for the life of me figure out why > chlorinated water would "rot" an asphalt roof. > As for evaporation, if you limit the amount of roof that you use, and > "flood" it during the collection period the temp rise is kept quite low and > evaporation is acceptable. This is great as most of us don’t want to swim > in 100F water anyway. Course you are using the whole roof to refill during > rainy times so I’ve not seen this to be a problem either. > Bill Roosa > "a man with an experience is never at the mercy of a man with a theory" > Author unknown >>>>Run your filter outlet to the top of the roof and let it squirt out >>>>through holes in a header pipe that runs along the peak. Collect >>>>the now warmer water in eves and run it through a filter to keep >>>>the dirt out… My parents do this and it works fine… >>>What kind of roof(s) are we talking about? >>Asphalt shingles? >>>I’ve seen leaking pool panels rot out galvanized drip edge, roofing >>>nails,and valley. I don’t think copper would fare much better when >>>exposed to this caustic substance. >>How about covering the roof with a layer of EPDM rubber with a layer >>of fiberglass window screen above that to help the water spread out vs >>trickle in rivulets over the surface? >>>Evaporation could be a problem. It is prolific enough from the surface >>>of a heated pool. >>Over 4×4 sleepers on 4′ centers, with clear polycarbonate over that? >>The materials might cost $3/ft^2 (30 cents/ft^2 for EPDM plus 50 cents >>for the window screen plus $1.50 for the polycarbonate, plus the 4×4s >>and ridge pipe), but it would probably last a lot longer than plastic >>pool heaters. You could also use it for solar heating and AC, a la >>Thomason, using a 2:1 CaCl2/LiCl solution… >>>If you put the black plastic directly on the roof then rot may occur. >>That might be a problem if the plastic leaks or the underside of the >>roof is underventilated, with a poor vapor barrier in the attic floor, >>but those situations seem avoidable… >>Nick >Our resident genius at play (Nick Pine). I like this application for >EPDM, too. I think there is still a possibility of roof rot if >applying anything over, say, an asphalt (fiberglass shingle) roof. It >mainly would occur if water was able to sneak in between the shingles >and (in the updated case) EPDM. High humidity areas may have >additional problems. I can’t stress this enough because the goal is >inexpensive methods of heating water (for whatever purpose) and >destroying a roof prematurely is counterproductive. If one was to >re-roof (over a given area) using EPDM vulcanized onto the tin tagged >felt then this would be a good approach in my view. One might >substitute plastic wood 1×2(using stainless screws) for PT as the >latter will eventually warp and/or rot. Lay the screen down and 1x >directly on it. A bead of polyurethene caulk will futher discourage >roof leakage where the screws penetrate (EPDM is supposed to be self >sealing, but…) Tack on new greenhouse plastic every few years as a >replacement item or after a hurricane/windstorm. That would be cheap >enough. I think this one’s a runner. Anyone care to try it? Maybe try >it on a large shed or even a tilted ground mount if they’re concerned >about being a guinea pig. >Dave
Response:
- Hide quoted text — Show quoted text ->> >> How about covering the roof with a layer of EPDM rubber with a layer >> >> of fiberglass window screen above that to help the water spread out vs >> >> trickle in rivulets over the surface? >> The screen may not be needed if a deposit of minerals roughens the EPDM. >Deposit of minerals roughens the EPDM? > Maybe. >Do you mean a glazing of dried chlorine on the rubber? > I was thinking of calcium or magnesium. >I would think it would reflect light? > Bad news. We might dissolve it with acid once in a while. >> >…I like this application for EPDM, too. >> It would go over the sleepers, so the screwholes would be 4" above >> the roof surface… >At the surface where the 4×4 (or whatever size sleeper) meets the EPDM >chlorinated water would potentually ooze under the sleeper and >rust/rot a non stainless lag bolt and/ or the PT wood. > I’d screw the sleepers to the roof, over the asphalt shingles, then lay > the EPDM over the sleepers and roof, with a fold where the sleeper meets > the roof, then screw the polycarbonate through the EPDM into the sleepers. >Why a 4×4? Why not a shallower airspace? > The polycarbonate might sag, and we might want enough space for natural > airflow to remove water vapor from LiCl… > Nick
I had it upside down. Sleepers on top of the EPDM. Now it makes sense. This way (draped EPDM) would allow for roof breathing. There might still be a wind load question, of course. What if one used the EPDM on a reroof? That stuff wouldn’t budge once vulcanized. Plastic wood 1x with 50 year caulk underneath. polycarbonate screwed into the slats. One could do just a section of the roof with flashing at the edges to seal where the EPDM stops and shingles begin. I would venture to guess that this would last a long time and be capable of withstanding the weather. Areas hit by snow would have to keep the snow/slush from entering in where the feeder pipe is above otherwise an ice dam may warp/break the poly. Nick’s opened up a slew of possibilities with this ubiquitous material. Dave
Response:
OK let me be a little more exact since you are not getting it When the sun comes up and the roof heats up to 80F the pool pump diverter valve redirects the filtered pool return water through the pipe that squirts out on the roof. The water is collected in the eves and returned to the pool slightly warmer. If the sun goes behind a cloud or it just is not ‘Hot" enough the diverter valve does not redirect the flow At which time the roof drys out. When the sun sets the roof cools and the diverter valve directs the return water to the pool at which time the roof drys out. It is really no different than the normal roof wet / dry cycle for a "rainy" location. OH yea, My parents home shows no shingle rot after 20 years. Does have a non-discoloration where the chlorine has kept the roof clean though. Bill Roosa
– Hide quoted text — Show quoted text -> Hi Bill, > If the shingle stay saturated with water then any chlorinated water that > reaches the core of the "asphalt shingle" would be in contact with the > rag core, yes rags. GAF shingles utilize old cloth as the central core > of the shingle so the fibers might be destroyed if saturated with > chlorine on a regular basis. > Offgridman > Is it the general consensus that pool water rots asphalt?! > I have seen no evidence of this and can’t for the life of me figure out why > chlorinated water would "rot" an asphalt roof. > As for evaporation, if you limit the amount of roof that you use, and > "flood" it during the collection period the temp rise is kept quite low and > evaporation is acceptable. This is great as most of us don’t want to swim > in 100F water anyway. Course you are using the whole roof to refill during > rainy times so I’ve not seen this to be a problem either. > Bill Roosa > "a man with an experience is never at the mercy of a man with a theory" > Author unknown >>>>>Run your filter outlet to the top of the roof and let it squirt out >>>>>through holes in a header pipe that runs along the peak. Collect >>>>>the now warmer water in eves and run it through a filter to keep >>>>>the dirt out… My parents do this and it works fine… >>>>What kind of roof(s) are we talking about? >>>Asphalt shingles? >>>>I’ve seen leaking pool panels rot out galvanized drip edge, roofing >>>>nails,and valley. I don’t think copper would fare much better when >>>>exposed to this caustic substance. >>>How about covering the roof with a layer of EPDM rubber with a layer >>>of fiberglass window screen above that to help the water spread out vs >>>trickle in rivulets over the surface? >>>>Evaporation could be a problem. It is prolific enough from the surface >>>>of a heated pool. >>>Over 4×4 sleepers on 4′ centers, with clear polycarbonate over that? >>>The materials might cost $3/ft^2 (30 cents/ft^2 for EPDM plus 50 cents >>>for the window screen plus $1.50 for the polycarbonate, plus the 4×4s >>>and ridge pipe), but it would probably last a lot longer than plastic >>>pool heaters. You could also use it for solar heating and AC, a la >>>Thomason, using a 2:1 CaCl2/LiCl solution… >>>>If you put the black plastic directly on the roof then rot may occur. >>>That might be a problem if the plastic leaks or the underside of the >>>roof is underventilated, with a poor vapor barrier in the attic floor, >>>but those situations seem avoidable… >>>Nick >>Our resident genius at play (Nick Pine). I like this application for >>EPDM, too. I think there is still a possibility of roof rot if >>applying anything over, say, an asphalt (fiberglass shingle) roof. It >>mainly would occur if water was able to sneak in between the shingles >>and (in the updated case) EPDM. High humidity areas may have >>additional problems. I can’t stress this enough because the goal is >>inexpensive methods of heating water (for whatever purpose) and >>destroying a roof prematurely is counterproductive. If one was to >>re-roof (over a given area) using EPDM vulcanized onto the tin tagged >>felt then this would be a good approach in my view. One might >>substitute plastic wood 1×2(using stainless screws) for PT as the >>latter will eventually warp and/or rot. Lay the screen down and 1x >>directly on it. A bead of polyurethene caulk will futher discourage >>roof leakage where the screws penetrate (EPDM is supposed to be self >>sealing, but…) Tack on new greenhouse plastic every few years as a >>replacement item or after a hurricane/windstorm. That would be cheap >>enough. I think this one’s a runner. Anyone care to try it? Maybe try >>it on a large shed or even a tilted ground mount if they’re concerned >>about being a guinea pig. >>Dave
Response:
I see, I was incorrectly thinking that they were saturated by a continouse feed method. What part of the country are they located in? – Hide quoted text — Show quoted text – > OK let me be a little more exact since you are not getting it > When the sun comes up and the roof heats up to 80F the pool pump diverter > valve redirects the filtered pool return water through the pipe that squirts > out on the roof. The water is collected in the eves and returned to the > pool slightly warmer. If the sun goes behind a cloud or it just is not > ‘Hot" enough the diverter valve does not redirect the flow At which time the > roof drys out. > When the sun sets the roof cools and the diverter valve directs the return > water to the pool at which time the roof drys out. > It is really no different than the normal roof wet / dry cycle for a "rainy" > location. > OH yea, My parents home shows no shingle rot after 20 years. Does have a > non-discoloration where the chlorine has kept the roof clean though. > Bill Roosa >Hi Bill, >If the shingle stay saturated with water then any chlorinated water that >reaches the core of the "asphalt shingle" would be in contact with the >rag core, yes rags. GAF shingles utilize old cloth as the central core >of the shingle so the fibers might be destroyed if saturated with >chlorine on a regular basis. >Offgridman >>Is it the general consensus that pool water rots asphalt?! >>I have seen no evidence of this and can’t for the life of me figure out > why >>chlorinated water would "rot" an asphalt roof. >>As for evaporation, if you limit the amount of roof that you use, and >>"flood" it during the collection period the temp rise is kept quite low > and >>evaporation is acceptable. This is great as most of us don’t want to > swim >>in 100F water anyway. Course you are using the whole roof to refill > during >>rainy times so I’ve not seen this to be a problem either. >>Bill Roosa >>"a man with an experience is never at the mercy of a man with a theory" >> Author unknown >>>>>>Run your filter outlet to the top of the roof and let it squirt out >>>>>>through holes in a header pipe that runs along the peak. Collect >>>>>>the now warmer water in eves and run it through a filter to keep >>>>>>the dirt out… My parents do this and it works fine… >>>>>What kind of roof(s) are we talking about? >>>>Asphalt shingles? >>>>>I’ve seen leaking pool panels rot out galvanized drip edge, roofing >>>>>nails,and valley. I don’t think copper would fare much better when >>>>>exposed to this caustic substance. >>>>How about covering the roof with a layer of EPDM rubber with a layer >>>>of fiberglass window screen above that to help the water spread out vs >>>>trickle in rivulets over the surface? >>>>>Evaporation could be a problem. It is prolific enough from the surface >>>>>of a heated pool. >>>>Over 4×4 sleepers on 4′ centers, with clear polycarbonate over that? >>>>The materials might cost $3/ft^2 (30 cents/ft^2 for EPDM plus 50 cents >>>>for the window screen plus $1.50 for the polycarbonate, plus the 4×4s >>>>and ridge pipe), but it would probably last a lot longer than plastic >>>>pool heaters. You could also use it for solar heating and AC, a la >>>>Thomason, using a 2:1 CaCl2/LiCl solution… >>>>>If you put the black plastic directly on the roof then rot may occur. >>>>That might be a problem if the plastic leaks or the underside of the >>>>roof is underventilated, with a poor vapor barrier in the attic floor, >>>>but those situations seem avoidable… >>>>Nick >>>Our resident genius at play (Nick Pine). I like this application for >>>EPDM, too. I think there is still a possibility of roof rot if >>>applying anything over, say, an asphalt (fiberglass shingle) roof. It >>>mainly would occur if water was able to sneak in between the shingles >>>and (in the updated case) EPDM. High humidity areas may have >>>additional problems. I can’t stress this enough because the goal is >>>inexpensive methods of heating water (for whatever purpose) and >>>destroying a roof prematurely is counterproductive. If one was to >>>re-roof (over a given area) using EPDM vulcanized onto the tin tagged >>>felt then this would be a good approach in my view. One might >>>substitute plastic wood 1×2(using stainless screws) for PT as the >>>latter will eventually warp and/or rot. Lay the screen down and 1x >>>directly on it. A bead of polyurethene caulk will futher discourage >>>roof leakage where the screws penetrate (EPDM is supposed to be self >>>sealing, but…) Tack on new greenhouse plastic every few years as a >>>replacement item or after a hurricane/windstorm. That would be cheap >>>enough. I think this one’s a runner. Anyone care to try it? Maybe try >>>it on a large shed or even a tilted ground mount if they’re concerned >>>about being a guinea pig. >>>Dave
Response:
>> I’d screw the sleepers to the roof, over the asphalt shingles, then lay > the EPDM over the sleepers and roof, with a fold where the sleeper meets > the roof, then screw the polycarbonate through the EPDM into the sleepers. >I had it upside down. Sleepers on top of the EPDM. Now it makes sense. >This way (draped EPDM) would allow for roof breathing. There might >still be a wind load question, of course.
I’ve lived with a single-layer polycarbonate roof for about 6 years with no wind problems. >What if one used the EPDM on a reroof?
Remove the shingles and tarpaper and glue EPDM to the sheathing? >That stuff wouldn’t budge once vulcanized. Plastic wood 1x >with 50 year caulk underneath. polycarbonate screwed into the slats.
I’d just screw nail the sleepers on through the shingles, drape the EPDM over them, and screw the corrugated polycarbonate over the EPDM into the sleepers, leaving no holes in the EPDM where it touches the shingles. Nick
Response:
> I see, I was incorrectly thinking that they were saturated by a > continouse feed method. What part of the country are they located in?
Baltimore MD, but my mom and dad live in south western Ohio – Hide quoted text — Show quoted text -> OK let me be a little more exact since you are not getting it > When the sun comes up and the roof heats up to 80F the pool pump diverter > valve redirects the filtered pool return water through the pipe that squirts > out on the roof. The water is collected in the eves and returned to the > pool slightly warmer. If the sun goes behind a cloud or it just is not > ‘Hot" enough the diverter valve does not redirect the flow At which time the > roof drys out. > When the sun sets the roof cools and the diverter valve directs the return > water to the pool at which time the roof drys out. > It is really no different than the normal roof wet / dry cycle for a "rainy" > location. > OH yea, My parents home shows no shingle rot after 20 years. Does have a > non-discoloration where the chlorine has kept the roof clean though. > Bill Roosa >>Hi Bill, >>If the shingle stay saturated with water then any chlorinated water that >>reaches the core of the "asphalt shingle" would be in contact with the >>rag core, yes rags. GAF shingles utilize old cloth as the central core >>of the shingle so the fibers might be destroyed if saturated with >>chlorine on a regular basis. >>Offgridman >>>Is it the general consensus that pool water rots asphalt?! >>>I have seen no evidence of this and can’t for the life of me figure out > why >>>chlorinated water would "rot" an asphalt roof. >>>As for evaporation, if you limit the amount of roof that you use, and >>>"flood" it during the collection period the temp rise is kept quite low > and >>>evaporation is acceptable. This is great as most of us don’t want to > swim >>>in 100F water anyway. Course you are using the whole roof to refill > during >>>rainy times so I’ve not seen this to be a problem either. >>>Bill Roosa >>>"a man with an experience is never at the mercy of a man with a theory" >>> Author unknown >>>>>>>Run your filter outlet to the top of the roof and let it squirt out >>>>>>>through holes in a header pipe that runs along the peak. Collect >>>>>>>the now warmer water in eves and run it through a filter to keep >>>>>>>the dirt out… My parents do this and it works fine… >>>>>>What kind of roof(s) are we talking about? >>>>>Asphalt shingles? >>>>>>I’ve seen leaking pool panels rot out galvanized drip edge, roofing >>>>>>nails,and valley. I don’t think copper would fare much better when >>>>>>exposed to this caustic substance. >>>>>How about covering the roof with a layer of EPDM rubber with a layer >>>>>of fiberglass window screen above that to help the water spread out vs >>>>>trickle in rivulets over the surface? >>>>>>Evaporation could be a problem. It is prolific enough from the surface >>>>>>of a heated pool. >>>>>Over 4×4 sleepers on 4′ centers, with clear polycarbonate over that? >>>>>The materials might cost $3/ft^2 (30 cents/ft^2 for EPDM plus 50 cents >>>>>for the window screen plus $1.50 for the polycarbonate, plus the 4×4s >>>>>and ridge pipe), but it would probably last a lot longer than plastic >>>>>pool heaters. You could also use it for solar heating and AC, a la >>>>>Thomason, using a 2:1 CaCl2/LiCl solution… >>>>>>If you put the black plastic directly on the roof then rot may occur. >>>>>That might be a problem if the plastic leaks or the underside of the >>>>>roof is underventilated, with a poor vapor barrier in the attic floor, >>>>>but those situations seem avoidable… >>>>>Nick >>>>Our resident genius at play (Nick Pine). I like this application for >>>>EPDM, too. I think there is still a possibility of roof rot if >>>>applying anything over, say, an asphalt (fiberglass shingle) roof. It >>>>mainly would occur if water was able to sneak in between the shingles >>>>and (in the updated case) EPDM. High humidity areas may have >>>>additional problems. I can’t stress this enough because the goal is >>>>inexpensive methods of heating water (for whatever purpose) and >>>>destroying a roof prematurely is counterproductive. If one was to >>>>re-roof (over a given area) using EPDM vulcanized onto the tin tagged >>>>felt then this would be a good approach in my view. One might >>>>substitute plastic wood 1×2(using stainless screws) for PT as the >>>>latter will eventually warp and/or rot. Lay the screen down and 1x >>>>directly on it. A bead of polyurethene caulk will futher discourage >>>>roof leakage where the screws penetrate (EPDM is supposed to be self >>>>sealing, but…) Tack on new greenhouse plastic every few years as a >>>>replacement item or after a hurricane/windstorm. That would be cheap >>>>enough. I think this one’s a runner. Anyone care to try it? Maybe try >>>>it on a large shed or even a tilted ground mount if they’re concerned >>>>about being a guinea pig. >>>>Dave
Response:
- Hide quoted text — Show quoted text ->> I’d screw the sleepers to the roof, over the asphalt shingles, then lay >> the EPDM over the sleepers and roof, with a fold where the sleeper meets >> the roof, then screw the polycarbonate through the EPDM into the sleepers. >I had it upside down. Sleepers on top of the EPDM. Now it makes sense. >This way (draped EPDM) would allow for roof breathing. There might >still be a wind load question, of course. > I’ve lived with a single-layer polycarbonate roof > for about 6 years with no wind problems. >What if one used the EPDM on a reroof? > Remove the shingles and tarpaper and glue EPDM to the sheathing? >That stuff wouldn’t budge once vulcanized. Plastic wood 1x >with 50 year caulk underneath. polycarbonate screwed into the slats. > I’d just screw nail the sleepers on through the shingles, drape the EPDM > over them, and screw the corrugated polycarbonate over the EPDM into the > sleepers, leaving no holes in the EPDM where it touches the shingles. > Nick
The EPDM would be vulcanized onto tin tagged 30lb felt (tar paper). Yes, if you melted the stuff directly onto the sheathing you would be hating life later. If the 4×4’s were lagged into the trusses (rafters) and EPDM drapped and screwed over that then I would deem this quite weather-able as EPDM roofing is a very resilient and strong material. The proof is in the pudding. If it has worked in the field (an application) for a reasonable period of time them it should be good to go for the next experimental phase. Our goal here is to make the sun competitive (thermally) with subsidized fossil and/or nuclear fuels in a mannor which is acceptable to building standards and aesthetics. A tight rope walk at best. Let us encourage all in this quest. Dave
Response:
Anybody know a good source for EPDM? I might want to do my whole roof in it, and just collect heat from the south-facing sections (new house, new roof, all options wide open). I might even use a dark color other than black, sacrificing some collection efficiency but gaining some in aesthetics… Jim Sutton
… – Hide quoted text — Show quoted text -> How about covering the roof with a layer of EPDM rubber … > Nick
Response:
> Anybody know a good source for EPDM? I might want to do my whole roof > in it, and just collect heat from the south-facing sections (new > house, new roof, all options wide open). I might even use a dark color > other than black, sacrificing some collection efficiency but gaining > some in aesthetics… > Jim Sutton > … > How about covering the roof with a layer of EPDM rubber > … > Nick
Call around to wholesale roofing suppliers. Talk them into selling to you. (represent yourself as a contractor of some type), Dave
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