While both types are made up of the same essential components re roofing over architectural shingle is a different case altogether.
Reroofing architectural shingles at top of roof.
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.
Drive nails at high points on the underlying roof the bottoms of the shingles.
It provides you with peace of mind knowing that you and your family are safe from rain snow hail wind heat and cold.
The standard practice is to limit to a total of two layers of shingles.
Having said that it will be nearly impossible to get a good looking quality installation.
At asphalt shingle starter course installation.
That s to avoid a raised ridge and to let the new full shingle course lay flat atop the original shingles.
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.
For a foolproof color scheme pick a roof that incorporates a shade on the house like the darker charcoal tones in the architectural shingles here which tie into the house s trim.
After that you should tear off old shingles before installing a new layer.
The quick answer is yes you can re roof architectural shingles over existing architectural shingles however you must check with the shingle manufacturer as well.
Timberline hd shingle in oyster gray about 97 per roofing square.
Notice that in re roofing the starter strip is an inch less in width than when installing new shingles over a fresh roof deck shown in our asphalt shingle roofing guide.
At the eave and the rake install u shape drip edge flashing made for reroof jobs.
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.
The two pieces should meet neatly at the corners.
Re roofing with 3 tab shingles are pretty straight forward.
Your roof is what keeps you protected.
Use 1 5 or 1 75 inch roofing nails.
In addition to composition shingles materials may also include any necessary roofing felt underlayment ice and water shield nails ridge vent and roof flashing details such as valley drip edge gable and chimney flashing and caulk.
Install the eave piece first then the rake piece over it.