Sunday, August 9, 2009

Flat Roof Repair

As the bathroom was coming to a wrap earlier this year, we went ahead and had the upstairs studio partially demolished. The work included ripping out 3 layers of ceiling containing the original 1-1/2" plaster with the radiant heating water lines exposing the existing flat roof 2x10 rafters. In all about 4" of ceiling material was removed along with the door and part of the non-load bearing wall was taken out.

In the first photo you can see the remnants of the door/wall removal, the old electric exposed. The concept for the wall removal is to open up the studio as a space to the main living area and allow more air flow from our sole AC in the studio. The wall between the living and studio now is a simple plane unobstructed. The new opening will be about 4 feet clear. Exposing the joists now allows us to put some insulation in the ceiling since we have none elsewhere.

After the demolition was complete and the dust had subsided, we realized we had more problems than a simple room remodel. We kinda anticipated something was up with the roof before demolition, but since we had to put buckets out to catch the drips. All of the framing around the masonry at the chimney was rotted along with several low points of sagging plywood. The main vertex of the sloped roof and the studio flat roof is where there was the worst damage.

It's been one rainy season here in Cincinnati, which has left almost no weekends to do flat roof work. Finally, a somewhat dry weekend came the 1st of August, a call from the roofer on Friday with a go for Saturday, it was on. Climbed up Friday afternoon, swept ponds of water off the roof. The second photo shows the roof area dry prior to Saturday rip off. I can't recall seeing the roof dry, ever. It offered a different perspective, the problematic spot had a previous patch as well.

The original intention was to pull out the low spots of rot, replace plywood, build roof back up, and apply patch of new EPDM. We only had Saturday until the rain forcasted for Sunday. I should note, I'm in no financial condition to replace and repair the roof the way it should be done, maybe one day. The plan was to repair the bad spots over the studio and phase through the future repairs until we can eventually put on a new roof. Additionally, we had a sea of mechanical fastener patches across the roof that were starting to back out and peel up in need of attention. The third photo shows the area of rubber roof cut up, and the super wet underlying fiberboard.

The fourth photo shows how juicy it was/is under the rubber, wait a minute, isn't the rubber supposed to keep the water out? So as we dug throught the layers of history, here's how the roof has been constructed. The original roof was built up tar and gravel, check. An unsuspected second layer of rolled asphalt roof caught me by suprise. Finally, brown fiberboard has been mechanically fastened through all other layers, and to it EPDM roof membrane has been glued.

The fifth photo is what we ended up digging into, queue the 6pm trip to Home Depot to get more plywood and 2x10's. We had gotten way further into the roof than I expected, nor did I realized the extent of my roofing future. Having ripped up all the bad plywood, we had exposed a good portion of th studio roof to the sky. It was much easier to replace the bad 2x10's from above. The sixth photo shows the view looking from in the studio, you can see the missing framing at the chimney.

After all the framing was good, we fastened new plywood down, then built up the roof by fastening down several layers of fiber board. We built up some roof pitch where there once was the large pool with fiberboard. It was about 8pm and starting to get dark about the point we started putting the new EPDM down. Between 4 of us, we had already patched the sea of fasteners and in about an hour, we were flashing around the chimney, everyone way ready for a shower.

It didn't rain that night so the final two photos are the next morning, 'how did we do?' inspection. Everything looked much better, climbing up the ladder and seeing pitch where there once was none is comforting. You can see in the photo the darker 'form flashing' that ties the EPDM to the brick chimney. Also note the darker patches all over the roof, why they ever put that many holes in a membrane is beyond me. I'll chalk that one as a 'Gened up' decision.

There are two other lower spots that probably have to do the same remedy on in the next couple years. Since the replace we had a good 2" rain, the next day revealed only a couple of small puddles over the studio, a significant difference from before. The roofer said all the patches will probably keep the roof dry, maybe long enough for the sponge factor to start drying out a bit. On Sunday we cleaned up a couple spots, and we have been dry ever since.

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