Doing it properly will keep you without problems for 20 or 40 years.
Shingle roofing layers.
Beveled wood pieces called horsefeathers must be laid along the thick edges of the shakes to make a fairly flat surface.
First of all multiple layers of shingles simply means layering a new asphalt shingle roof on top of the old one rather than stripping the roof completely to expose the sheathing and replacing it with new shingles.
Framing includes the roof trusses that sit at the top of your house and support the weight of all the materials used to build your roof.
California roofing laws cover everything from licensure of the roofing company to the types of shingles that must be used to the slope of the roof.
Before you reshingle a roof read our step by step guide for adding new shingles over old ones.
Roof shingles are installed in such a fashion that each seam or joint is overlapped by a shingle further up the roof.
That limit pertains to roofs with up to a 4 12 pitch.
Most building codes allow up to two layers of organic or fiberglass asphalt shingles.
Shingles protect sloping rooftops from the effects of rain snow and hail while providing an attractive crown for the house.
Most building codes allow this but is it a good idea.
Roofing layers from the framing to the shingles so we ll start at the bottom of the deck and work our way up through all the roofing layers until we reach the shingles and sunshine above your roof.
When it s time to replace your roof there are several factors that might lead your roofing professional to recommend adding shingles on top of your existing layers.
California roofing codes establish a list of rules that all builders and contractors must adhere to in order to ensure safe building practices within the state.
Any more than two layers of shingles can be too much for the roof to handle even if the local building codes don t outlaw it.
In most areas building codes allow for up to two layers of shingles installed on a roof.
Keeping a solid roofing layer of shingles is an important way to avoid water damage and leaks.
Roof shingles consist of a series of individual overlapping components that when laid together in rows or courses starting at the bottom edge of a roof form a barrier designed to repel water snow and ice.
Asphalt shingles can be laid over cedar shakes or shingles however this is a roofing project best left to pros.
Pros to overlaying a shingle roof.
Here are the pros and cons.
But contractors who spoke with angie s list say best practices call for stripping the roof down to the wood deck to inspect it before installing a new roof.
Examine the edge of the roof to make sure there s only one layer of shingles currently installed.