Roofing and rain catchment

[ben2go]

We are planning to remod our house this spring.In the process, the roof will be redone,because we are adding on.The water catchment system will mainly be for flushing toilets,irrigation,and outdoor chores.However,we have been having droughts through the mid and late summer,so we would like the option of using the water for consumption.The plan is to divert the water into a cistern,which is a 1500 gallon septic tank that is new and has never been used.I will use the standard filtration and water treatment for the house.The problem is my local roofing suppliers(not Lowe's or Home Depot)are not up on this.They tell me that galvanized,coated steel,and aluminum will leave chemicals in the water that a treatment system can't remove.I was looking into a metal roofing that screws down on one side and snaps to the next section.Can't remember the exact name or manufacture.Anyone doing something like this or have a clue as to what I should be looking for in a metal roof?

[ben2go]

I forgot to ask about gutters.We are getting conflicting info on aluminum,galvanized,and plastic rain gutters for drinking water.I wanna use white PVC,but PVC has been known to cause cancer.The same can be said about galvanized and aluminum also.We don't have any trees with in 250 feet of our house,so we shouldn't need leaf guards.Any thaughts on this?

[Welshmom]

Good questions. I'm wanting to set up some rain barrels off my house and barns next year for garden, livestock, and emergency household if needed. I'm interested in the answers or suggestions folks here have!

[CamM]

Most things I have read on the subject say steel is an option. Maybe the chemicals that come off are minimal or can be filtered, despite what the store people say. If you don't want steel you can buy wood shakes or slate, which might be more expensive. Aluminum probably isn't coated with anything because it doesn't rust.
I think PVC is inert once it is formed. The chemicals that for it cause cancer for the people who work in the factories. Even if you don't have trees, it might be good to have a diverter, which removes the first couple of gallons that have bird feces and dust.
Do a little more searching around online about steel. I think you'll fine it's a viable option despite the zink coating.

[woodsman]

What exactly were the roofing suppliers recommending for rainwater collection? Perhaps something they had in stock?

From what I was able to gather steel roofing with various finishes, is probably the best surface. You'll have more problems with bird feces, dust, pollen, leaves, etc. contaminating roof surface than with chemicals unless you live in urban/industrial area or around places with airborne pesticides or fertilizers.

There is a type of steel roofing called R Panel which is shaped out of a roll of sheet metal, can be cut to specified lengths and comes in different finishes and gauges. You can probably find a a manufacturer near you.

[bearkiller]

Out here in the People's Republic of California the painted metal roofing is manufactured by a local company. I've been through their plant and used their products. The paint finish is a multicoat lacquer process that I feel pretty comfortable using to catch rainwater.

No need to use standing seam roofing; it is simply added expense. The three foot wide panels simply overlap a seam. The panels are screwed down onto a substrate ( I simply used purlins attached to the rafters) with painted to match screws and neoprene washers. Nothing toxic there I can see.

My main house has a comp roof, half covered with moss, LOL. A newer addition has the metal roof. Guttering is steel, painted white with leaf screening. In late fall after leaf fall I take the backpack blower up there and blow off the roof. We see an average of 48 inches of rain and I dump it into a 5000 gal plastic tank. Works like a charm. When the dirt load in the tank gets too uggy I clean it out.

You can set it all up with a hand pump for easy access to the water. Or an electric pump, too. I'm off grid so do most things by hand.

bearkiller

[MELOC]

my grandfather used galvanized roofing and a diverter. he would only collect during a good heavy rain and after the roof was washed off. when he felt it was good to go, he diverted it to the cistern. i imagine that strategy would work with most any type of metal roofing. most of the easily mobile nasties would wash away and you could then divert to the cistern.

[manygoatsnmore]

If you are really worried about the chemicals or toxins or whatever, you can always set up a drinking water filter with Black Berkey filters - a little spendy, but they filter out pretty much EVERYTHING! I just got my filters and made my own housing with 2 5 gallon food-safe buckets. I have the worst well water - comes out of the ground brown! When I put it through the Berkeys it comes out crystal clear and tastes great. (And no, I don't get paid for recommending them, lol!) Now if they only made one for the clothes washer....

[ben2go]

Originally Posted by CamM

Most things I have read on the subject say steel is an option. Maybe the chemicals that come off are minimal or can be filtered, despite what the store people say. If you don't want steel you can buy wood shakes or slate, which might be more expensive. Aluminum probably isn't coated with anything because it doesn't rust.
I think PVC is inert once it is formed. The chemicals that for it cause cancer for the people who work in the factories. Even if you don't have trees, it might be good to have a diverter, which removes the first couple of gallons that have bird feces and dust.
Do a little more searching around online about steel. I think you'll fine it's a viable option despite the zink coating.

Wood has presevities which may not be able to be filtered.Aluminum will corrode after a few wet dry cycles.You maybe correct on the PVC being ok after forming or fabrication.I do plan to use a diverter system that diverts and catches the first few gallons of water.This is known as a washer system,but that's kind of miss leading.There's no washing envolved,just diverting the first few gallons of contaminated water.

Originally Posted by woodsman

What exactly were the roofing suppliers recommending for rainwater collection? Perhaps something they had in stock?

From what I was able to gather steel roofing with various finishes, is probably the best surface. You'll have more problems with bird feces, dust, pollen, leaves, etc. contaminating roof surface than with chemicals unless you live in urban/industrial area or around places with airborne pesticides or fertilizers.

There is a type of steel roofing called R Panel which is shaped out of a roll of sheet metal, can be cut to specified lengths and comes in different finishes and gauges. You can probably find a a manufacturer near you.

Luckily for me,they confess up really quickly about there lack of knowledge about rain catchment for consumption.I live in a rural area where there is no agricultrual operations any more.Most land is being developed which is taxing our water and power grid.My area has already put in a new water line to another source of water.Our area has already nearly drained two lakes due to,to many users.Our area population has exploded by something like 700% since 1995.So I decided to take the steps to prevent my house hold from being hit hard by water restrictions,again.

Originally Posted by MELOC

my grandfather used galvanized roofing and a diverter. he would only collect during a good heavy rain and after the roof was washed off. when he felt it was good to go, he diverted it to the cistern. i imagine that strategy would work with most any type of metal roofing. most of the easily mobile nasties would wash away and you could then divert to the cistern.

This is the plan that I am currently going with.


Someone mention standing seam roofing.I hate the stuff.I can never get the crimper to run the seam correctly.The roofing I mention in my first post is a coated steel snap loc system.It's basicly the same thing as standard metal roofing,except the sheets are narrower and the fastners are hidden under the snap loc seam.I was looking into it because there's fewer holes to allow water leaks.

Here is roughly the same plan I have.My system will hopefully be a little neater.
http://ersson.sustainabilitylane.com/rainwatr.htm

After looking into prices.I have decided to go with a "plastic" cistern and a couple of old plastic 55 gallon barrels for rain barrels for watering.I have weeds for a lawn and would like to keep that to help prevent soil erosion.It's very drought tolerant.

Thanks for the help.I am always researching my ideas.The internet,what a wonderful thing.Couldn't do this without it.

Another thing I wanted to mention was,my area is very slow to adopt new technologies like water catchment,solar power,straw bale construction,and other alternative building methods.Six years ago,I was denied the permits to install solar power.Then,it was only used in my area for the amber alert system and to run traffic cameras.Now you can get permits but it's a real struggle.

[woodsman]

I found this standpipe filter collector which is self cleaning as all debris from the roof bigger than .011 fall down or get washed away from the very fine screen. It's probably not as effective in a really heavy downpour when the flowing rain water takes up the whole diameter of the standpipe but it looks like it would take care of most of the dirt before it reaches the cistern.

[woodsman]

ben2go, the screws with neoprene washers work really good - I haven't seen a single leak in an R panel roof which we installed over 2 years ago and we had some rains that dropped 3 inches of rain within very short time and hurricane force winds. You just have to be as careful when you fasten the panels down so you don't overtighten the screws either breaking the washer or bending the sheetmetal profile out of shape. The only seams you have to deal with are the ones along the edges which we sealed with a sticky caulking rope before placing the next sheet overlapping it. All screws go through the tops of the reinforcing ridges so the water falls away from them further reducing possibility of the leak. The only fault I can find with this type of roofing is that without a ceiling enclosing the attic space, in a heavy downpour, it gets really noisy - as if a crash of rhinocerouses run across the roof

[The Paw]

Based on your situation as described, if the plumbing is going to be accessible during the remodel, I would plumb parallel systems.

In other words, I would plumb it so that the shower, laundry, and toilets all ran off the cistern, while kitchen sink and bathroom sink ran off of "city water".

You could have a float switch in your cistern so if it falls below 20% or so, city water gets pumped in to top it off.

This way, you probably only have to filter the cistern down to 5 microns or so, and you don't have to worry about ingesting any residual chemicals, dust, etc. It would also handle 80% plus of your water needs at reduced cost. If you have a dry spell, your city water connection picks up the slack.

[ben2go]

Originally Posted by woodsman

I found this standpipe filter collector which is self cleaning as all debris from the roof bigger than .011 fall down or get washed away from the very fine screen. It's probably not as effective in a really heavy downpour when the flowing rain water takes up the whole diameter of the standpipe but it looks like it would take care of most of the dirt before it reaches the cistern.

Thanks for the link.I was thinking of building something along those lines.

Originally Posted by woodsman

ben2go, the screws with neoprene washers work really good - I haven't seen a single leak in an R panel roof which we installed over 2 years ago and we had some rains that dropped 3 inches of rain within very short time and hurricane force winds. You just have to be as careful when you fasten the panels down so you don't overtighten the screws either breaking the washer or bending the sheetmetal profile out of shape. The only seams you have to deal with are the ones along the edges which we sealed with a sticky caulking rope before placing the next sheet overlapping it. All screws go through the tops of the reinforcing ridges so the water falls away from them further reducing possibility of the leak. The only fault I can find with this type of roofing is that without a ceiling enclosing the attic space, in a heavy downpour, it gets really noisy - as if a crash of rhinocerouses run across the roof

My garage uses coated steel for the roof and siding.It uses the self tapping screws and neoprene washers.So far they have held fairly well.My garage is roughly 5 or 6 years old.I am considering this same system to roof the house.Some of the websites that I have visited say not to use coated steel roofing for water catchment.Their argument is that the coating can peel and contaminate the water.Seems to me that a stand pipe would deal with this issue.

Originally Posted by The Paw

Based on your situation as described, if the plumbing is going to be accessible during the remodel, I would plumb parallel systems.

In other words, I would plumb it so that the shower, laundry, and toilets all ran off the cistern, while kitchen sink and bathroom sink ran off of "city water".

You could have a float switch in your cistern so if it falls below 20% or so, city water gets pumped in to top it off.

This way, you probably only have to filter the cistern down to 5 microns or so, and you don't have to worry about ingesting any residual chemicals, dust, etc. It would also handle 80% plus of your water needs at reduced cost. If you have a dry spell, your city water connection picks up the slack.

I had thought of something along these lines.I was planning to re-plumb the house any way.My thoughts were to replace the plumbing just like it is and have valves in my utility room to switch from city water to the cistern.My water bill is already high.Filling a 1500 gallon cistern would get me a fine during times of drought when we are on water restrictions.Speaking of that.Our water restrictions were just lifted after all the rain we had through the end of November and through December.It is something that I will ask my water company about.I have family that works for the water company,so that's an easy one to take care of.



I guess I should have included this in my original post.I am planning to use solar water heater with tankless electric back up.I will use solar panels and a small battery bank to power the water pump(s).Eventually the house will be completely solar powered.Grid tie if my power company and building inspector will allow it.

Thanks for the ideas.I will be putting a plan on paper in the next month or two.

[The Paw]

Originally Posted by ben2go

I had thought of something along these lines.I was planning to re-plumb the house any way.My thoughts were to replace the plumbing just like it is and have valves in my utility room to switch from city water to the cistern.My water bill is already high.Filling a 1500 gallon cistern would get me a fine during times of drought when we are on water restrictions.Speaking of that.Our water restrictions were just lifted after all the rain we had through the end of November and through December.It is something that I will ask my water company about.I have family that works for the water company,so that's an easy one to take care of.

I think you could set the float switch to only dump in a couple of hundred gallons, or you could just have the switch trigger an alarm/light that would then allow you to transfer an acceptable amount manually.

I think if you have valves connecting the two systems, they have to be those special anti-backflow valves.

[YuccaFlatsRanch]

Unless you have a very small roof 1500 gallons of storage will not be enough. You can catch 600 gallons per 1000 sq ft of roof area. Doesn't take long to fill 1500 gallons. Here is a good link about rainwater harvesting.

http://www.twdb.state.tx.us/publicat...3rdedition.pdf

[ben2go]

Originally Posted by The Paw

I think you could set the float switch to only dump in a couple of hundred gallons, or you could just have the switch trigger an alarm/light that would then allow you to transfer an acceptable amount manually.

I think if you have valves connecting the two systems, they have to be those special anti-backflow valves.

I could rig the float switch as you have described.I am trying to keep an open mind on this.You are also correct on the anti back flow check valves.

Originally Posted by YuccaFlatsRanch

Unless you have a very small roof 1500 gallons of storage will not be enough. You can catch 600 gallons per 1000 sq ft of roof area. Doesn't take long to fill 1500 gallons. Here is a good link about rainwater harvesting.

http://www.twdb.state.tx.us/publicat...3rdedition.pdf

You're right on.1500 will be small.The plan is to start out with a 1500 to 2000 gallon tank and add a second one late on.I haven't done the math,but the new roof should be right around 1000 square feet.Our roof has a low pitch,which will slow water flow,and has less area than most standard roofs with a 6/12 pitch or greater.I am not sure what the new roof pitch will be.I'm thinking it's 3/12 or 4/12.We rarely get snow or ice here so our roofs don't have to have a lot of pitch to aide in shedding snow build up.Thanks for the link.

[WisJim]

Here is what some folks I know are doing, and have been doing for decades:
http://www.geopathfinder.com/9566.html Their website shows what they do and why they do it.

[solarisvahalla]

Hello, We are using standard corrugated tin roofing for our water catchment, and you can visit our website for more information at: http://www.svfarm.org
We have been doing this for 3 years, and we do use a filter system which my
dad would be glad to give you more information on if you like.
Be very careful using anything else! I studied, and researched for about 2 years before setting up ours at the farm.


Kelsey
Solaris Valhalla

[woodsman]

We built a 16'x16'x7' cistern into the foundation of our house - it gives us about 13,000 gallon storage capacity. We figured that should be enough to keep us supplied with water through the dry season which might last 4 months as both of us use no more than 40-50 gallons a day total (navy showers, water saving toilet, etc.). Too bad that when we planned this we also didn't plan to have as many animals as we do now

We get over 60,000 gallons of water dumped on our roof every year. The problem is that it comes in spurts so sometimes we get 20" inches of rain within a two week period and a lot of it overflows... Long story short - we should have build the cistern at least twice the size or not raise any animals that use LOTS of water.

Basically you have to calculate all your needs - get the rainfall mean monthly values for your area and calculate precisely what kind of a buffer you 'd need to never run out.

[ben2go]

Originally Posted by WisJim

Here is what some folks I know are doing, and have been doing for decades:
http://www.geopathfinder.com/9566.html Their website shows what they do and why they do it.

That is good setups.Thanks for the link.I live on a hill but my cistern would have to be on the side of the road,in front of the house.To many mischevious people in my area for that.I can't go under ground with the cistern because of the septic system.I only have 4/10 of an acre currently.We are looking into some acreage in the future,so it would be good to be able to relocate the system.

Originally Posted by solarisvahalla

Hello, We are using standard corrugated tin roofing for our water catchment, and you can visit our website for more information at: http://www.svfarm.org
We have been doing this for 3 years, and we do use a filter system which my
dad would be glad to give you more information on if you like.
Be very careful using anything else! I studied, and researched for about 2 years before setting up ours at the farm.


Kelsey
Solaris Valhalla

Oh yea.My water will be filtered.I am undecided on a reverse osmosis system or UV light treatment.Thanks for the link.Nice looking veggies on there.

Originally Posted by woodsman

We built a 16'x16'x7' cistern into the foundation of our house - it gives us about 13,000 gallon storage capacity. We figured that should be enough to keep us supplied with water through the dry season which might last 4 months as both of us use no more than 40-50 gallons a day total (navy showers, water saving toilet, etc.). Too bad that when we planned this we also didn't plan to have as many animals as we do now

We get over 60,000 gallons of water dumped on our roof every year. The problem is that it comes in spurts so sometimes we get 20" inches of rain within a two week period and a lot of it overflows... Long story short - we should have build the cistern at least twice the size or not raise any animals that use LOTS of water.

Basically you have to calculate all your needs - get the rainfall mean monthly values for your area and calculate precisely what kind of a buffer you 'd need to never run out.

That's a great system.If we build a house I may consider an under foundation cistern.Our current house is built on block piers roughly 20 inches high.Old place we have.When we redo the plumbing we are going with water conserving fixtures.We got roughly 23 to 26 inches of rain this year.It's been a really dry year.We should have had 32 to 36 inches of rain.We had 3 months of no rain this past summer.Plus we were already short of rain fall from the previous year.I did the calcs and we will have more roof area than I estimated.With the addition of roof over the front deck,a large divided room addition,and adding a small bathroom,we will have roughly 1800 sq feet of roof.However I will be using a couple of rain barrels along with the cistern(s).Assuming .62 gallons per sq. ft. and using the entire roof,I would get 1116 gallons per inch of rain.Does this seem correct?We rarely get more than an inch of rainfall all at once.It's been raining here for 3 days and we haven't gotten 2 inches yet.After tonight we may have 4 inches by the end of the day tomorrow.Thanks for sharing.