Second Layer Of Roof Shingles

Shingles laid over an existing roof do not last as long as their typical lifespan.

Second layer of roof shingles.

That in itself eats away at the savings. The second layer of shingles will trap heat which can result in the decomposition of both roof layers. Lay the second row of shingles. You could be adding weight to your roof with a second layer that your house cannot handle.

This 1 2 tab has to be cut off where it hangs off the left edge of the gable roof. How to shingle over existing shingles and how to shingle a roof how to install roof shingles shingle layout lines h. Water travels between the layers often coming through another spot meaning patch jobs and even identifying the source of the leak is difficult at best. That helps your final layer of shingles look flat with a proper installation.

The additional layers trap extra heat which causes damage to the roof. Set the first shingle of the second row back a half tab 6 inches 17 centimeters from the edge of first shingle on the first row and so that the bottom of its tabs just touches the tops of the cutout slots on the shingle below. If the structure can support the added weight a typical 20 square 2 000 square foot reroof will cost at least 1 000 less than a tear off job. Another issue is that when you add in the second layer it can add extra weight to your roof.

The second layer is also more difficult to install properly compared to new shingles. That second layer of shingles won t last as long. Flashing around roof penetrations and sidewalls can be compromised. Attach with nails along the top edge of the strip.

Rip cut the starter strip or starter pieces so that they butt up against the second course of existing shingles and are even with the front edge of the existing roofing. Advantages of reroofing most building codes allow two layers of organic or fiberglass asphalt shingles on roofs with a 4 12 pitch or less and three layers on steeper roofs. Roofing second layer of shingles roofing. This step is important because it brings the underlying surface back to a level height consistent with the rest of the roof plane.

Plus depending upon the size of your roof you ve added multiple tons of weight which could pose a big problem if there is significant snow accumulation. Add a layer of shingles over the newly repaired area before you install your second layer of shingles. Use a starter strip or cut pieces for a starter course.