You should always put a new underlayment over the old shingles. Whether boards are put down or you go direct over the old shingles is very much a function of the metal roofing product you choose. Homeowners looking to replace an aging roof have two basic options: they can either strip off the old roof and replace it with a new asphalt roof, or they can install metal roofing over the existing asphalt shingles. Unless building codes require it, there is usually no need to tear off the old roof.
Installing metal roofing over. In this video we go over how we put a metal roof over shingles on our mobile home.
Can you avoid tearing off your old asphalt shingle roof by putting a steel roof over it? Most codes now allow no more than two layers of roofing before requiring a complete tear-off. So, if your roof has two layers, it may require a complete tear-off, even though steel is lighter than asphalt. Codes vary, so call your local . My answer often surprises people.
However, it is based upon experience with tens of thousands of installations over many years. Water vapor build-up and attendant mold and rot are not reasons alone to avoid installing metal over shingles. Roofers can install a vented metal roof over existing shingles , which would eliminate the vapor problem.
Step by step instructions and videos on how to install metal roofing over an existing shingle roof. The second way to install a metal roof over a shingle roof is with the use of purlins or battens. The purlins are screwed or nailed down to the roof deck, depending on how the metal roofing manufacture has testing for their roofing panels, and then the metal is installed to the purlins. After completing construction on a new barn, the customers asked me about the possibility of putting a metal roof on their home to match the roof on the barn. A little reluctantly, I agreed and thus began a 15-year journey of installing more than.
I would like to know what the pros and cons are in regards to putting on a metal roof over your excisting shingles verses removing the shingles , and also if the warrenty is any different if you leave the shingles on. Like all such questions, more details are required before a definitive opinion can be . I am writing as someone who has been involved in the production of residential metal roofing , including tens of thousands of projects, for over years. My perspective pertains primarily to metal shingle roofs which are more forgiving of going over uneven surfaces than are some vertical seam metal roofs. Steel roofing offers many benefits over slate tiles or asphalt shingles. Manufacturers provide 30-year warranties on metal roofing products.
Use furring strips to build a slat board on the roof, then mount the . Metal roofing is resistant to fire, rot, and termites. Adding a metal roof to your home over your old shingles may not be a good idea. Here are some pros and cons for installing a metal roof over shingles. Read on to see why we would choose metal over shingles.
Because metal roof materials are noncombustible, they typically have a Class A fire rating (the most resistant).
Most metal roofs applied over a combustible material such as wood shingles. Now, assuming the average cost of $10. The low-end cost for steel shingles installed over -top of the existing roof would be around . With the accessories include a metal roof can cost about the same as, or within a few hundred dollars of, a shingle roof on an average home.
And considering that our premium and standard metal panels come with 40-year paint warranties ( with many metal roofs even lasting over 1years with proper maintenance), the.