What to look for in roofing job: ply, flashing questions


We are half-way to having our roof replaced down to the rafters (demo has happened, we get new ply and new shingles next week). Unfortunately, I discovered Angieslist after I signed a contract, and our roofer really has been as dismal as the folks on Angieslist have reported. It’s been kind of a disaster so far - many things broken, poor scheduling, etc.

We’re a little concerned that he’s going to do a shoddy job putting ply back on our roof, so I plan to be here when he’s putting it on to make sure he doesn’t skip anything. Trouble is, I know nothing about roofing!

Any hints on what I should be watching for? (he’s had major trouble with leaks, according to Angieslist).

Particularly, should there be caulking between the sheets of ply after they go up to seal the joints?

Separate from his work: our chimney has some really ugly flashing on it. Can that be removed and redone when they put the ply on? How do we get the tar off? (we’ll probably need to do this part ourselves)


down to rafters is a hell of an undertaken.
no need for caulkin in plywood cracks. just put the plywood up there, dry it in , shingle it.
replace chimney flashin if its all tared up.
how to remove tar? do it in cold mornin use small ax, chop the tar off,
tear out old metal, replace with new metal.



you keep using the term “ply,” and I am assuming you mean plywood. The term “ply” in roofing has a much different meaning to us if plywood is indeed what you are meaning to say. Plies to a roofer are typically layers of felt/membrane (asphalt saturated, organic, fiberglass, etc.) used in the roof system.

Assuming you mean plywood and not ply, then my one bit of advice is to make sure the contractor uses H-clips when installing the plywood. This provides a small gap between the sheets of plywood so it can move (expand/contract). It also gives the plywood ridgitiy between the rafters. You don’t need caulking between the plywood sheets.

With regard to leaks, if the contractor is known to put down leaky roofs, I would have steered clear of them to begin with. If you are stuck with the contractor, then you can take some precautions by pay a little more for certain items. First, you could have the roofer install ice & water shield along the roof perimeter, and around any roof penetrations. This may already be priced into the roof along the eaves, so I would ask the contractor in a sly way how much ice & water shield he is going to install. His answer will be your clue as to what is or isn’t included.

Next, I would be curious if the contractor included in his bid the replacement of ALL flashings and counterflashings. Some roofers are only there to replace the shingles, and they intend on re-using the metal flashings. I would want them all replaced with new metal flashings even if it raises the total cost. Of course, in my way of thinking, the contractor should plan on replacing the flashings anyway, but some don’t.

You won’t need to remove the asphalt-based roofing cement from the chimney flashings if they are being replaced. The contractor simply needs to remove the existing flashings and install new flashings. You should also take note what kind of metal he is using for flashing. If they are using aluminum, G90 galvanized, Kynar finished galvanized, copper, etc… You should probably ask him, since you obviously won’t know the difference unless he ends up installing copper (not likely).

The most important thing you have that tells you what to expect is the proposal/contract that you signed. The proposal should outline exactly what the contract intends to do with regard to the roof replacement. If it isn’t clear and spelled out, then you should not have signed the proposal. This is one way some contractors get jobs, Company A bids the work with new shingles and all new flashings, Company B bids the shingle replacement only without new flashings. Oh, you want new flashings? Well then, that will be a change-order in the amount of $$$$. Now the cheaper roofer actually becomes the more expensive roofer!

Thanks for the info on what to look for. Yes, this roof is a huge undertaking - the previous one leaked badly, creating a gigantic mold problem on the inside.

Our contract is very clear about what needs to be done - he’s just having trouble following through with all the items (“get it done and get out” kind of attitude). Therefore, I’m worried he’ll skimp on what he’s agreed to provide, and I wouldn’t know!

Thanks again!

And yes, I do mean plywood. Right now we have wooden rafters, and nothing else (except a goopy, metal mess around our chimney where there is the old flashing). Our second-floor lath and plaster are exposed - that’s why we’re limited on being able to fire/rehire - we need it on before any rain comes.

thanks again!


Leaving a roof open for the weekend is crazy. No wonder he has problems with damaged homes.

Your flashing sound like they need to replaced.

Not all flashings need to be replaced. That just adds unnecessary expense to the project. Why would you replace perfectly good flashings?

I agree with lefty, tearing off a roof and roof deck and leaving it open all weekend it crazy. The contractor should have torn off half the roof and installed new deck and at very least felt underlayment if not the shingles also. To tear-off more in a day than you can put back on is not a good roofing practice. To leave it open all weekend, is just asking for trouble. I hope the contractor’s insurance is up to date.

If they don’t show up bright and early Monday morning, make sure you get on the phone and demand they get your house dried-in.