Flat Roof Materials
Flat Roof Material TIPS
- Hot-mopped asphalt is ancient technology and prone to leaks
- STOP asphalt oxidation with copper on your roof
- Synthetic roof membranes like EPDM are best
- Take photos of seams and flashings of new roof to help diagnose future leaks
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Do you have an old-fashioned ballasted flat roof? This is a roof covered with gravel.
The gravel is used to hold down the roofing materials in high winds and it also protects the old asphalt from ultraviolet (UV) light from the sun. UV rays really hurt asphalt.
The sun's UV rays break apart asphalt molecules. The asphalt wants to get comfortable so it grabs oxygen out of the air.
This is called oxidation. When this happens, the asphalt molecules cross link. If too many molecules cross link, the asphalt gets stiff and hard.
You can significantly SLOW the oxidation of asphalt by introducing copper onto the roof. The copper ions go where the oxygen goes but it doesn't allow the asphalt to cross link.
Leaks Hard To Find
If you have one of these roof systems and a leak(s), forget about locating them. It will be virtually impossible! The gravel does a fantastic job of hiding leak locations.
The use of synthetic membranes has just about eliminated the need for gravel on roofs. Why?
Because many of these new roof membranes are glued down to the roof sheathing. Not only that, the new membranes contain materials that resist UV degradation. If you can install a new flat roof without gravel, DO IT! It will make future leak finding much easier.
The synthetic membranes have many other benefits. Imagine being able to cover your house with just one giant piece of roofing material? No seams to worry about! It is possible if you find the right roofer and get the right membrane. Some of the membranes come in widths up to 50 feet!
Free & Fast BIDS
The Actual Material
Have you ever seen how a flat tire is fixed on a tubeless tire? The rubber patch is actually vulcanized to the tire's inner surface or wall with special solvents.
The patch and the tire basically become one in the same. This is how some of the new membranes work. As a roofer seams pieces together or makes cuts for flashings, they can actually weld pieces of material together.
Synthetic Rubber Is Best
Some of the top performing materials, in my opinion, are the synthetic rubber roofing compounds. These are commonly referred to as EPDM and CSPE materials.
I have installed these materials on many of my jobs where low-slope roofs have caused leak problems using conventional materials. These membranes work very well where old rolled asphalt materials, hot mopped asphalt, or even shingles were used before.
Not DIY Friendly
The only disadvantage, I can see with them is that they are not DIY friendly. In other words, you will probably need to locate a professional to install them.
You must remember that this technology is not really used much in residential work. Commercial roofers use these materials most frequently.
There are many residential roofers in large cities and small towns all over the USA that have experience with these materials.
Where Can You Use Membranes?
The membranes have many uses in residential work. You can use them on shed roofs that commonly have low slopes or on a Cape Cod style house with a dormer. There are many older houses that have low sloped worn out tin roofs. The membranes are far cheaper to install than replacing with tin or copper!
How about chimney crickets? These are little hip roofs that are found behind chimneys. Membranes work well here.
Does your house have the old fashioned tin box gutters? If so, you can reline the gutters with these membranes instead of expensive tin. An additional benefit is that you don't have to maintain the membrane like tin. Tin requires periodic cleaning and repainting.
If you have a flat roof on your house and do install a new membrane roof, I suggest that you perform an annual inspection. Since the roof is flat or nearly so, it will be easy to walk around.
Take Photos BEFORE Leaks Happen
I urge you to inspect the roof for the first time immediately after it is installed. Take photos of the roof and close up photos of all flashing locations and seams.
Keep these photos in a safe place and make sure they are clear. As you perform your annual inspection, you can refer to the photos to see if an area, seam, or flashing has begun to change. Photos are wonderful tools. As they say, "The lens doesn't lie."
Don't Do Old Asphalt Again
Don't be tempted by the lower price (possibly!) to do a quick mop over of your existing asphalt roof. Asphalt is simply old technology and is prone to failure.
The system is dependent upon expert workmanship for long term high performance. Excellent workmanship is harder and harder to find these days.
Great Membrane Warranties
Also, you'll be surprised at the warranties you can get with the membrane materials. When you sit down and analyze the cost versus the benefits, you'll do well by upgrading to the membranes.
So far, every membrane roof I have installed has been leak free. Some have been on for more than twenty years. If I had a low-slope on my own house I can tell you that I would put an EPDM or CSPE membrane on it so fast your head would spin.
Leaks cause anxiety. Don't get cheap when it comes to your roof. Buy the best and relax.