Why installing new shingles over old shingles can be good.
Framing new roof over old.
The remedy may be stripping the roof and nailing 1 2 in.
But if you have an old home with a decaying roof especially a low pitched roof removing the old roof and replacing it may not be practical.
Box beam gable framing new gable overhang is framed in the form of a box beam hanging off of a new layer of roof plywood roof sheathing cantilevered over the top of the 3 layers of rigid insulation.
Place the top of each starter shingle firmly against the bottom of the shingle immediately above it and even with the eaves then nail it into place.
When necessary to tie the new rafters into the house framing the workers cut into the old roof to make the secure connections.
When roofing over your existing shingles can be a good idea.
In this case you can build a new roof over the old with a caveat.
Build the rafters on the ground and then lift them onto the roof.
Plywood over old sheathing or bolstering undersize rafters with new lumber but let a seasoned professional make the call.
Let s start with the good.
The amount of rafters needed will depend upon the size of the roof.
The sheathing must be stripped from the old roof for a couple feet along the bottom to get the new ceiling joists in.
The solution is changing the roof pitch or building a new roof at a higher pitch than the old roof.
Use 1 5 or 1 75 inch roofing nails.
The rafters should be in a triangular form with an additional piece of 2 x 4 going straight up the center.
Many arizona homeowners with shingle roofs do decide to roof over their existing shingles because.
You can frame a new roof over the old but it will need to be designed for the span and pitch.
If you are building a new home putting an addition on an existing home or replacing your roof down to the rafters you will need a new roof frame.
You must not build the new roof directly over the old.
While it might look possible to use the old ceiling joists they would need to be grade checked to make sure they meet the present code.
The rafters should be placed every 2 4 inches for proper support of the roof.
How much does it cost to frame a new roof.
You can save money because there s no dump fee for removing your old roofing and there s no need for additional felt paper over the old roof.
A new coat of shingles over decaying shingles will cause your roof deck to decay.
When you should tear off your roof and start from scratch instead.
If a roof is relatively new and these symptoms are widespread suspect product defects inadequate ventilation faulty installation.
The exposed edges of the 3 layers of rigid insulation are no longer exposed.
And the variables of design don t stop there the builder must determine the pitch or slope of the roof and use that measurement to figure the total rise from the wall s cap plate to the roof ridge.
