Porch over living space -EPDM failure-Must repair correctly


#1

Here’s my tale of woe. The porch off our master bedroom sits above our dinning room and it’s leaking. The house is 5 yrs old and the porch was built with very little slope (perhaps 1" every 8-10 ft). Here’s how it was built: The base layer is a enhanced plywood flooring called Advantec. First they put down a layer of black rubber material that used glue to seal joints. I didn’t think this was good enough so they screwed down a layer of insulation board (the type normally used for EPDM install) over the black rubber. Then the EPDM. Over this we installed a duckwalk system with 2x4 floaters to which was attached wood decking on top. We did put a layer of EPDM on the bottom of each 2x4 for protection. One big challenge is that the deck has 4 wooden posts projecting through it to support a roof above. I now realize the EPDM install was poor. Some of the seams around the posts were suspect and apparently the crew installing the wood decking dropped stuff and cut the EPDM. Today, we are going to tear everything off back to the plywood and start over. We had water pooling on the EPDM because of lack of slope and I believe because the insulting board got compressed in spots from foot trafic. The original contractor wants to do EPDM directly over the plywood and promises a meticulous install this time. This deck has light foot trafic only. I HAVE to get this right this time or my wife will kill me. HELP!


#2

hi my name is jessie im from maine.i do single ply rubber,and it sounds like you had a roofer that dosn`t know what he is doing. your posts should be wrapped in uncuered rubber membrane,with the proper adhesives,also you should install fiber board,down to the plywood before the rubber,fstened with anchor plates.


#3

Post pics of the detail work prior to covering everything in decking.
If you go over the plywood directly every little splinter, high fastener,uneven joints ect must bet taken care of first. And the wood should be screwed not nailed nail pops will kill the epdm.


#4

Correction to my original post. The FIRST layer down was EPDM. The LAST layer, over the fiberboard, was Carlisle TPO (heat sealing of seams).


#5

I suggest pourable sealer pockets around the posts. Its hard to seal tpo to wood directly.
The suggestion about going over the plywood directly still applies.


#6

Guys, thanks for the suggestions. We discovered that the major failure here was the seal of the TPO to the special drip edge - a special aluminum with a TPO material bonded to it. During the original installation, they got glue on this edge (the glue they were using to bond TPO to the fiberboard) and as a result, the heat sealing didn’t hold.