had a roofer say that there would be no warranty on the roof because it was ship lap, and not on new plywood .
Really?? zat true…never heard that before? all the old roofing material has been stripped down to ship lap, so one layer of new duroid atop felt of course is what whats going on.
Replies
Yup!!! They are trying to do that.
Got involved as a consultant to a roofer/insulator about 15 years ago. At that time BP/Emco had in their literature that the shingles should be installed on panelized product. This was due to seasonal expansion and shrinkage of wider boards due to attic moisture (actually house moisture getting to the attic where it shouldn't be!!)
The 80-100 year house he had installed new shingles on the old still-in-good-shape boards had a spring running through the basement (name of town- Springhill). The company had also blown the walls/slopes/attics thus tightening the house to natural drying air leakage. In the end moisture was dripping in the attic. Everyone the owners/contractor talked to said the attic needed more ventilation, so more was installed and the attic got.....wetter.
The owner called BP and during the conversation, the panel sheathing/warranty issue came up, resulting in a very unhappy homeowner. I ended talking to the BP engineer in Montreal and he had no idea about "wet/damp" houses, moisture movement with air leakage, stack/chimney effect in buildings, that increasing venting in some houses makes the attic wetter!!!!! All he could talk about was vapour barriers and code venting (which we were already beyond).
So in the end the house got dried out in the basement, attic got airsealed, dripping stopped and shingles have no problems (except that there may not be a warranty. Hey, they're about 16 years old now)
Bill Rose (a roofing, insulation, ventilation researcher from the University of Illinois) in 1990's JLC Q&A section, said that manufacturers seem to be taking every effort to void warranties to make up from what he percieves as declining quality of shingles.
I saw another example of this yesterday in a house inspection. This light coloured roof (grey/white; 13 years old) had granule loss on the south facing slope severe enough that I told the buyer a few small sections should be replaced so the whole might make it to 20 years!!!! When I was a contractor installing roofing in the 80's, a "Frost White" colour shingle roof (Domtar Truseal 3-in-1 tab with 10 year warranty) would last 24-27 years.
The manufactuere of the shingl;es will have a data sheet and copy of their install instructions and warrantee on the web. Just Google.
Some warrantee it and some don't.
My recollection of the most common wording was in install instructions something like - "Shall be installed over clean smooth sheathing with no loose knots, splits, or gaps larger than 1/4" in size..." Also recommendations to patch over larger gaps with tin scrap.
Since then we have found that it is better and cheaper to plan to re-sheathe the roof with new ply or Advantec to eliminate the problem
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Piffin
I certainly never roofed as many houses as you but do you really feel there is a problem with roofing over shiplap sheeting? Just curious.
I guess you could sheet over it with 3/8th ply couldn't ya, that wouldn't be all that expensive.
Doug
Only if the boaards have shrunk back to lve gaaps like 3/8" between them.i'm just explainng from the manufacturers POV. I don't think the original claim made by thi guy's roofer is true. Most shingle laayers soon learn though that they can lay shingles faster over a smooth sheathedeck than over old half worn boaarding
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!