Should I remove my existing roof before installing the new roof?
Under current laws a homeowner can have up to three (3) layers of composition and shakes or shingles before being required to tear the roof off. (Check your local codes/ordinances/CC&R’s etc…)
Brazil Quality Roofing, Inc. recommends tearing off your existing roof. Why?
- Find problems – and fix them. When you remove the old roof there is a probability that there may be some dry-rotted wood under the existing roof. When the old roof is removed we can check the entire roof deck for any rotten wood or other problems. Any rotten wood will then need to be replaced to STOP the rot from spreading, and other issues can be addressed at this time.
- Start fresh. Removing the old roof and starting with a clean, smooth surface is always recommended. When the new roof is nailed directly to the smooth deck, you not only get a straight even look, but your new roof will perform better and last longer. Leaving the old roof on can cause a “lumpy” effect making the new shingles look like they have lumps under them because of the old roofing material does not provide a smooth surface to install the new shingles over. Water is able to shed quicker on a smooth, flat surface, hence, enabling your roof to perform better and last longer.
- Risk vs Reward. A typical tear off of a roof can be approx. 10% – 12% of a Re-Roof price. Replacing dry-rotten wood found after the roofing is complete can cost upwards 100% of the contract price. Future repairs will require double the effort, and double the materials to replace shingles when you have multiple layers of shingles on the house.
CAUTION: Three layers of composition shingles, although acceptable by most codes, may not be practical. A wood shingle roof can weigh approx. 300lbs. per square (10’x10′ area) and an additional layer of 30 year composition can weigh an additional 240lbs per square. With two (2) roofs you are at about 540lbs per square. Lightweight concrete roof tiles start at 590lbs per square and go up to about 720lbs per square. Adding the third (3rd) layer of shingles on brings your weight up to approx. 720lb per square roof. That is as heavy or heaveir than a lightweight tile roof! Anytime that much weight is put on the roof, a structural engineers report is required before you put the weight on the roof to make sure the existing trusses can handle the new dead load.
Preventative maintenance is always recommended, hence, Brazil Quality Roofing, Inc. recommends tearing off the roof for quality and peace of mind.