Railing on EPDM flat roof
FrankFulton
| Posted in General Questions on
We have a flat EPDM roof with two walk-out doors, and currently no railing. It’s a major safety hazard (and a costly “miss” by us and our home inspector!).
How can I add a simple railing around the perimeter of the flat roof, without puncturing the roof and risking leaks? The railing will be for safety and decorative purposes – we won’t actually use the flat roof as a walk out deck (although from below it will look like a deck, once the railing is installed).
Thank you.
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Replies
I sympathize with not wanting additional penetrations in the roof.
however not knowing what the roof structure looks like it is hard to tell if a railing could be attached to the edge or not.
The standard answer would be screw posts through the roof and use boots[similar to what one would use for a pipe penetration] on each one.
A code compliant railing can be made with posts 8 feet apart, so maybe not that many posts.
Perhaps it would be just as easy to replace the doors with a window unit, or fixed glass
I guess the cheapest possible way is to ask the local building inspector how many screws in the door make it not a door any more........
We just installed 2 railings on Friday, one for a flat roof, one for a 2nd floor patio. I did not want to penetrate the membrane either, so we lagged the posts through the fascia into the nailer/header.
Thank you for the replies. Ill post a photo later, but we could secure part of the railing adjacent to the door frame, FWIW.
Jonathan, the edge of this roof has flashing and a 6” gutter. How did you address similar issues?
Also, here is the YouTube video I found - the approach looks solid, but how stable? and too few details.
https://m.youtube.com/watch?v=vqHpdXHNTWg
One other solution is a ballasted system such as this: https://www.keesafety.com/products/keeguard.
I would shy away from any ballasted rooftop systems. Those type of things have been disallowed in many/most commercial buildings for years due to unpredictable failures and then blowing off the building and hurting people or damaging property.
Play it safe. Either securely fasten the rail to the structure so that it will safely prevent someone leaning on it from falling over the edge, or remove the door so that the roof becomes inaccessible.
Bill
Thanks Michael and Bill.
Do you have any thoughts about the YouTube video, or other approaches that dont penetrate the EPDM membrane? I dont want to invite leaks.
Frank, I think the video you shared, which shows slightly raised blocks below posts that are face-screwed into the roof, is better than nothing, but not by much. Last year I built a rooftop deck and we had a similar discussion. We ended up getting custom stainless steel brackets welded, bolted them to the side of the rafters, and installed the EPDM around the new brackets using pitch pockets. It's safer to have steel penetrate the membrane than to have wood penetrate. Pitch pockets follow the idea in your video somewhat, but are a simpler, more durable solution--basically a raised plastic curb filled with waterproof sealant. Then the posts and deck framing can be bolted to the steel bracket.
That video looks to be screwing through the membrane still. That is usually the easiest but leak issues.
As others have said, the best is lagging into the edge. If you only need one post in the middle, you can split your gutter into two section or drop the gutter down bellow the bottom of the post. Don't know how your roof is sloping but can also do small parapet at the edge to direct the water towards one side and remove the gutter completely.
You can go around the gutter but that means welded posts with standoffs($$$).
Frank, it is not apparent from the picture, but the flat roof has a drip edge similar to the patio. Because of the space taken up by the soffit, we were not able to lag the posts below the drip edge, but instead through it. So the posts plates are still on the vertical face of the fascia and the lags are about 3” below the surface of the membrane. The gutter sits in the edge of the soffit, so it was a non-issue. On the ends we were able to lag through the fascia on the gable roof which is visible in the picture.
Akos/others,
In the video, he states he is glueing a 12x12 base onto top of the membrane (so as not to puncture), then securing the railing post into the newly glued-on base, and finally sealing over the base and new post, all without puncturing the original membrane. But he doesn’t present details, which is why Im posting here for expert/experienced feedback.
Thoughts?
Frank, if the EPDM is fully adhered to the substrate, it's probably over a fiberboard or foam substrate. The substrate itself is the most likely point of failure--I've had to tear up EPDM that didn't lay properly and the substrate itself pulled apart. If there was a lot of force on the railing I would be concerned with failure; it would be better with deck framing holding the posts together. It might be fine without but it's hard to know.
If there is no deck framing, I don't think that screwing down into 1 1/2" (or less) of blocking is nearly enough, considering the leverage you create when pushing on the top of a post 3' away. A 200-lb horizontal load 3' away from lag screws spaced 6" apart would create 1200 lbs of pullout force.
Frank,
To add to what Michael said: The 200 lbs loading he used is a specific IRC code requirement. It's worth making sure whatever you come up with is both safe and meets the building code.
Thank you all.
Martin, as a former roofer: Any additional ideas?