Roof

[LD]

The roof of our 2000 sq. ft. bungalow (straightforward gable, 4/12 slope, no skylights) needs to be redone.

We've asked 5 contractors to give us an estimate. 4 are in the same ballpark (i.e. $9,000 CDN), one is asking for TWICE that amount. He says that the roof "felt soft" when he walked on it, so he's added

4700 sq.ft. worth of 1/2" plywood (to put on top of the existing one) to his estimate. No other roofer mentioned "softness", but they did indicate that, should they discover rotten wood underneath the shingles, they would then charge us for the replacement (at $2.00 per sq. ft.).

Well, I don't like surprises. Nor do I want to replace wood that could still be in good condition.

Is there a way that I can assess the condition of the wood under the shingles WITHOUT removing them? What signs should I be looking for in the attic?

Also, is there a magic formula to calculate the size of a roof? None of the roofers have quoted us the same size.

Any and all information relating to having one's roof redone is appreciated.

[m Ransley]

Forget the double price guy.

Look from underneath in the attic, rott should be visible. Call the other guys back to see if they can help to look, and give a better idea on Sq ft. if any may be bad. If you see any it will be worse on top.

[HA HA Budys Here]

WOW! 9000.00 Canadian is more than 6700.00 American.

I had my roof done 2 years ago. Full tearoff and about the same size and slope as yours. Just under 3000.00 and that included all cleanup, disposal, and replacing 3- 4x8 sheets of plywood.

I'd get more quotes.

Forget the contractor who is planning, without it being necessary, to replace or overlay all of your decking with new. He's selling unneeded work.

Do not expect the contractors who already came out to bid to come out again and re-bid and answer more questions.

Rot, or water damage.

How far apart are they? That's called bid padding. Get more bids and ask for the roof's exact measurements, or measure it yourself.

I know plywood is about 3 times the cost as when I had my roof installed, but the contractor used full sheets only to correct damaged areas (below chimney, around a plumbing vent, and a spot where there was an existing roof patch) and quoted me the price of each sheet (4' x 8') not "per sq. ft. replaced."

[Tom Baker]

I'd suggest a base bid for tear off & shingle based on a specific set of materials. (#30 felt, 20 year shingles, edge flashing, for instance) Add a unit price for deck replacement. You would need to be available to walk the roof deck after tear off.

You can look at the underside of the deck, but that is not going to provide a final answer.

TB

[Andy Asberry]

Your first clue should be the 4700 sq ft to cover 2000 sq ft. Is he putting on 2 layers? Save your breath guys, I know the roof is a little more than 2000.

[Bruce]

I don't have any experience with Canadian roofing, but in Texas we have never had to replace an entire roofing deck in 11 years. If, by chance, you have 3/8" decking, that always feels soft, but doesn't mean that it should be replaced.

Normal procedure for us is to replace rotten decking using only the amount required to cover the effected area safely. We don't patch a small area with a whole sheet of plywood, we only use what is necessary.

If you don't have any leaks, you won't have any bad decking. When the roof is torn off the roofers will be able to see if there are any problems that you are not aware of.

This is fairly common to get different sizes from different roofers. Some measure from the top, some from the bottom, some just look at it and take a guess.

The easiest way I've found is to measure from the ground, divide the drawing into rectangles, calculate the dimensions, multiply the dimensions by the appropriate number for the slope of the roof (in your case a 4:12 should be multiplied by 1.06), and add on another

10-15% for cutting and waste, plus starter and hip & ridge shingles.

Since the roofers are quoting a price for the entire package, the number of squares doesn't matter. Just make sure you hire a qualified roofer, preferably one who is certified by a major shingle manufacturers.

A.&B. Construction