Above 85 f it is easy to tear the shingles or mar the granular coating.
Roof asphalt shingle installation.
Installing asphalt shingles over an existing shingle roof it s not ideal to install new shingles without removing the old ones but follow this pro advice if you do.
To install asphalt shingles start by installing underlayment and new flashing on the roof.
Starting at the bottom of the roof map out a guideline with chalk.
Installation temperature requirements for asphalt shingle roofs ideally shingles should be installed at temperatures ranging from 40 f to 85 f.
Although placing new roofing over old may be allowed by some codes roofovers tend to be inferior and won t last as long as a roof installed over stripped sheathing.
Continue to chalk additional guidelines based on the width of the shingle through at least four courses rows across the roof.
Then begin nailing the shingles to the roof working in rows and starting at the edge of the roof.
Use your chalk and tape measure to mark about 12 inches up on the roof for the first set of shingles.
Once you ve done that cut your shingles to size if they re not already.