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Metal Roof Installation Over Shingles

Medha Godbole May 13, 2019
Metal roof installation, especially over shingles, is not a cake walk. However, it surely isn't a real tough job either. The following information will tell you how to go about it.
Bored of seeing those shingles covering your roof? May be it is time for a change. How about having a metal roof over those shingles? Earlier, metal roofs were a part of houses which were designed only by architects. Recently, enough conventional houses too have them.
Even if the house does not have a metal roof, and there are shingles, the roof can be built over it. Although there are a few architectural and construction-related concerns, they will be described ahead. Take a look at the installation instructions:
#1 Gathering the supplies and tools is the fundamental task at hand. You will require:
  • Pine boards
  • 3-inch wood screws
  • 1¼-inch roofing nails
  • Hammer
  • Drill or screwdriver
  • 5/16-inch lap screws
  • Notching scissors
  • Closures
#2 Begin with making a slat board base on top of the shingles. You will have to lay some ¼-inch pine boards on your roof at every 2 feet. These will be attached to the roof with the help of 3-inch wood screws in each corner. The boards have to be laid from bottom to top.
#3 Around the perimeter of your roof, install a metal edging. For every 4-6 inches, nail the edging to the roof, using 1¼-inch roofing nails. The next thing to be done is to install metal roofing sheets, one by one.
On a single section of the roof, lay the sheets from top to bottom. Once again you will require 1¼-inch metal wood screws for fixing the metal sheets with the wood slat board base.
#4 With a distance of two feet, place the screws on each side, in the center, just for the first metal sheet on the roofing. The next sheet will ideally overlap the first one, and this pattern will be continued every time you install a new sheet.
#5 The next thing is installation of overlapping screws, post covering of the roof with metal sheets. Fix the sheets with the help of 5/16-inch lap screws at a distance of 4 feet from each other, wherever there is an overlapping of the metal sheets.
You can now install the metal trim along the edges of the roof and the top ridge. 1/4-inch metal wood screws, 2 feet apart, have to be fixed for this. For making the metal bend over the ridge, use notching scissors for notching the metal in the center. This is important when installing metal roofing over shingles.
#6 The bottoms of the metal sheets have to be closed. This portion will not be totally attached to the roof unlike other parts. ¼-inch metal wood screws, fixed at every 2 feet, can be used for fixing the bottoms to the roof.
#7 Finally, install closures by just pushing them in the openings. They will seal themselves, as they are self-adhesive on one side. These are useful in preventing water, insects, and other unwanted material from getting through the openings.
This was a basic overview of metal roof installation over shingles. When you actually do it, it might turn out to be more difficult than reading about it. However, you can always hire someone to do this for you. Remember, there will be some pros and cons of installing a metal roof over existing shingles.
You can install them if there are less than four layers of shingles on the roof. Otherwise, drop the idea. You can consult a concerned professional, in such a case. He shall also tell you about the installation cost and allied costs. However, if you are going to turn this into a DIY project, remember to take all the precautionary and safety measures.