Roof Under Second-Floor Porch

smitty286 · 06-13-2008, 01:32 PM

My house has an uncovered second-floor porch on top of a first-floor bedroom, such that the traffic surface of the porch is actually the roof over that room. The roof surface is roll asphalt covered by the previous owner with green outdoor carpeting. I noticed some water staining on the bedroom ceiling after the “spring thaw” this year, so I pulled up the carpet to reveal extensive water damage all the way through the roof decking and even into a few of the joists. There was clear evidence of puncture / tearing damage to the roll roofing in many areas, apparently caused by chair legs, etc being ground into the hot, soft surface in the summertime. I want my replacement to be a serviceable traffic deck, while (obviously) still being a watertight roof, but I’m having trouble finding an “off the shelf” solution.

One idea I did have would be to simply put down a new roll roof, then attach furring strips over it and build a standard wood deck on top of those. This has the added benefit of allowing me to build a level deck over the pitched roof, and since I have to replace the entire surface anyway, dropping it down a couple inches to accommodate the extra thickness isn’t a problem. I would probably have to use plywood sheathing instead of OSB so it doesn’t get compressed between the furring and the joists, but other than that I honestly can’t see a drawback to this approach; nonetheless, it somehow seems “hokey” to me – has anyone else seen another way to handle this situation?

**Ed the Roofer** · 06-13-2008, 02:14 PM

Get a professional roofing contractor to install a modified bitumen APP torch down roof membrane on the deck walk-out. It is very durable and will resist scuffing and tearing from foot traffic and chair or table legs.

If there is going to be a lot of traffic, install roof walkway pads on top of the finished membrane. A carpet will continually hold moisture on the roofing material, which degrades its properties.

Ed

Slyfox · 06-13-2008, 09:58 PM

If your going to install a deck over the roof than any roof system designed for flat roofs will work assuming it's installed properly.
Google "floating deck systems" and you will find instructions, materials, etc., needed to install the deck properly.

Ed's advice on hiring a pro is important, if you install the roof and leave it exsposed, leaks will be easy enough to get to, but if you cover it with a deck and it leaks, than you have to remove bits&pieces of the deck to get down to the roof.

OldNBroken · 06-13-2008, 10:41 PM

This is a project I HIGHLY recommend hiring out to a professional with proven experience in this type of work, not just anyone calling themselves a roofer. Not really a DIY project you have there.

smitty286 · 06-18-2008, 11:48 AM

Thanks Guys,

I didn't realize there was actually a product designed for applications like this (and it sounds like there's good reason why you can't just walk into Home Depot and pick it up, either). You've convinced me that this probably is indeed a job for a professional...

06-13-2008, 01:32 PM	#1
smitty286 Newbie Join Date: Mar 2008 Posts: 10	Roof Under Second-Floor Porch My house has an uncovered second-floor porch on top of a first-floor bedroom, such that the traffic surface of the porch is actually the roof over that room. The roof surface is roll asphalt covered by the previous owner with green outdoor carpeting. I noticed some water staining on the bedroom ceiling after the “spring thaw” this year, so I pulled up the carpet to reveal extensive water damage all the way through the roof decking and even into a few of the joists. There was clear evidence of puncture / tearing damage to the roll roofing in many areas, apparently caused by chair legs, etc being ground into the hot, soft surface in the summertime. I want my replacement to be a serviceable traffic deck, while (obviously) still being a watertight roof, but I’m having trouble finding an “off the shelf” solution. One idea I did have would be to simply put down a new roll roof, then attach furring strips over it and build a standard wood deck on top of those. This has the added benefit of allowing me to build a level deck over the pitched roof, and since I have to replace the entire surface anyway, dropping it down a couple inches to accommodate the extra thickness isn’t a problem. I would probably have to use plywood sheathing instead of OSB so it doesn’t get compressed between the furring and the joists, but other than that I honestly can’t see a drawback to this approach; nonetheless, it somehow seems “hokey” to me – has anyone else seen another way to handle this situation? Last edited by smitty286; 06-13-2008 at 01:54 PM.

06-13-2008, 02:14 PM	#2
Ed the Roofer Super Moderator Join Date: Jan 2007 Posts: 2,384	Roof Under Second-Floor Porch Get a professional roofing contractor to install a modified bitumen APP torch down roof membrane on the deck walk-out. It is very durable and will resist scuffing and tearing from foot traffic and chair or table legs. If there is going to be a lot of traffic, install roof walkway pads on top of the finished membrane. A carpet will continually hold moisture on the roofing material, which degrades its properties. Ed __________________ Stay Tuned For Our New Informative And Helpful Web Site, Coming Soon To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

06-13-2008, 09:58 PM	#3
Slyfox Residential Roofer Join Date: Jun 2008 Location: Struthers, Ohio Posts: 803	Roof Under Second-Floor Porch If your going to install a deck over the roof than any roof system designed for flat roofs will work assuming it's installed properly. Google "floating deck systems" and you will find instructions, materials, etc., needed to install the deck properly. Ed's advice on hiring a pro is important, if you install the roof and leave it exsposed, leaks will be easy enough to get to, but if you cover it with a deck and it leaks, than you have to remove bits&pieces of the deck to get down to the roof. __________________ God Family Country Work Play To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. *To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.*

06-13-2008, 10:41 PM	#4
OldNBroken Doing This Way Too Long Join Date: Jun 2008 Location: North Idaho Posts: 1,019	Roof Under Second-Floor Porch This is a project I HIGHLY recommend hiring out to a professional with proven experience in this type of work, not just anyone calling themselves a roofer. Not really a DIY project you have there.

06-18-2008, 11:48 AM	#5
smitty286 Newbie Join Date: Mar 2008 Posts: 10	Roof Under Second-Floor Porch Thanks Guys, I didn't realize there was actually a product designed for applications like this (and it sounds like there's good reason why you can't just walk into Home Depot and pick it up, either). You've convinced me that this probably is indeed a job for a professional...

Roof Under Second-Floor Porch