Shower Drain On Flat Roof

We’ve got a flat roof over a garage with about an 18-inch over hang. But we have got this giant.

We’ve got a flat roof over a garage with about
an 18-inch over hang. But we have got this giant ponding area and we need
to install a drain in the low spot. One of our favorite drains because it’s so cheap and it goes in so easy is this shower drain from Home Depot. This is what it looks like upside-down. We put it down on the roof first and kind of cut right around the edge using the drain as a template. There you see we’ve cut out a piece of the membrane and there our very precision-made cuts through
the plywood. Sorry, that was with a reciprocating saw that looks
like it must have got away from somebody. Then we put the drain itself in that hole to make
sure that it fits. I want to show you the difference between the
shower drain and the one next to it. This shower drain on the left is one that
requires access from the bottom. This drain has a clamp ring so you need access
from down below to put it all together. And plus, I don’t really care for this one because the
lip on it is just too small. Now the one we like has this white part to it. You just undo these bolts here and get rid of the
white and that’s what it looks like. And notice that it has four screw holes. You can just screw it right down to the plywood. This is what it looks like from the bottom. I love this drain because it has such a low profile, doesn’t stick up above the membrane. Looking down in the hole, you can see that we’ve got a stucco layer to cut through down below, about a three-inch hole. We did that with a stucco hole saw. Made a clean cut. Now putting the drain in place just to make
sure it’s fitting. Then we pull it out and put down this urethane sealant, then we press the drain back into the ceiling. And notice now we’ve installed the screws,
the drains in there tight. It’s permanent. Then we add more urethane sealant and smooth
it out flat. Then we lay down urethane coating because
it’s compatible with the urethane sealant and then we reinforce it with a layer of polyester fabric, and we press the fabric down into the perimeter
of the hole. The alternative to the expensive urethane coating is to simply use polyurethane sealant and cover it with roofers foil. Check out the video entitled
Shower drain with foil on flat roof. Now we need a strainer for the drain opening. Whatever you do, don’t use this diamond pattern downspout screen. It plugs up way too easily. I like the wire strainer because it has bigger openings. It doesn’t plug up so easily. You can get the wire strainer on eBay. Here’s a package of 15. Here’s one of 30. Be sure when you order it though you get the right size. This is a 2-inch strainer basket. This is another one that’s two-inch. You can get three-inch four-inch. Be sure you get the right size. When you’ve got a lot of leaves on the roof,
other debris, you want to use hardware cloth so you can make this big square screen. No matter how many leaves are on the roof,
it’s not going to plug it up. So that’s how to install a shower drain on a flat roof. Piece of cake. And plus it’s only 12 bucks. Get it at Home Depot. Check out more roof tricks and the
How to Bid It Right Program at

3 thoughts on “Shower Drain On Flat Roof”

  1. i just found your video and i have a ? I stay in a 2 story building with a flat top roof and when it rain the roof has so much water it could cave in. . If i use what you have in video the pipe have to go down to the first floor to drain so do i run the long pipe through both floors down to the kitchen drain? OMG I HOPE YOU GET THIS MESSAGE , WE NEED HELP. Do i need more than on drain?

  2. Viewers…please do not accept this hack advice. The installation is 100% illegal in the State of California and probably everywhere else. NEVER use a shower drain on anything other than a shower!!! Use a roof drain to handle roof drainage issues, that's what it's designed for. He's trying to sell you on cheap. Don't buy it. The roof drain is the weakest link on your roof. go here to learn how to do it right…

  3. love this! Many roof drains cost way too much! Will sika urethane construction glue work for this? im assuming your drain there is abs? do you wait for the first layer of glue to dry before you put urethane over the top of the cap?

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