# Flat roof decision



## HomeOwner74 (6 mo ago)

Hello, and thanks in advance for any advice that you can provide to me.

I bought my house in 2019, which last had the roof done about 15 years ago. There is a large section (several hundred sqft) of shingled roof that has a very low pitch, and I've been advised by several parties that this section should have a flat roof and not shingles. We've also been told it looks like this section has been patched before, and when we were remodeling a bathroom we found some mold from slow leaks along the exterior wall where it met the ceiling. This section of roof does have a few vents as well. The rest of the roof looks like it is in good shape.

We were hesitant to do a flat roof for aesthetic purposes, but I think we've talked ourselves into it to be "worry free", until it is time to redo our entire roof. 

The roofing contractor who was very competitive on price, and also the most thorough when examining our roof suggested the following:

Supply and Install SBS Firestone Roofing System which includes: 
1. Tear off existing layers of Roofing Down to Existing Wood Deck Replace any soft or rotted plywood at no additional cost. 
2. Supply and Install Owens Corning Ice and Water Shield as a Base Sheet Over Entire Supply and install Liquid Karnak 66 entire roof as second layer of protection Roof Deck. 
3. Supply and Install Firestone SBS Black Cap Sheet 
4. Install Fabric and Flashing where needed.

This would include a 20 year warranty. 


It seemed to me like this proposal mixed products from a few different manufacturers, so I wanted to make sure that sounded like a good solution. The roofing company is one of the larger ones in our area, as I understand it.

We received a quote from a different contractor in the same ballpark to install Liberty GAF flat roof solution, which looked better aesthetically to us, but a few contractors have advised against that solution for such a large portion of roof. 

Any advice would be very appreciated. Thanks!


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## SmartRooferLLC (Sep 5, 2021)

I'm in South FL. That first system seems off to me. I have the following questions:
1. Replace all bad plywood at no additional cost? What is his incentive to replace marginally bad wood? What about if all the wood is bad? Plywood is no longer cheap. It takes labor to replace bad wood. I am skeptical of "free" things.
2. You're right to think it odd to mix up manufacturers. The main low slope membrane components should be made by the same manufacturer. It's unusual to mix manufacturer's but it could be an availability issue - who knows? 3. Who is providing the 20 year warranty? Does it include Labor and Material? 
4. I like GAF Liberty but a self adhered system requires meticulous installation and the roof deck should have positive slope at least 1/8/ft.

A lot of details to go over. I'm happy to answer any questions you might have. You can email me at [email protected] 

Been doing this a long time. Not interested in getting the work - just like to share the knowledge acquired through back breaking decades in this God forsaken trade (meant in jest (mostly))


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