Trim 15 year-old shingles

Snap a chalk line and have at it with a circular saw. Go slowly and don't use a blade with too many teeth.

On 3/22/2011 3:06 PM Willie The Wimp spake thus:

I was going to suggest the roofer's knife until I read that last sentence.

How about buying a few boxes of utility knife blades and using that? Pain in the ass and will dull the blades in no time flat, but should work.

They use a roofing blade for a utility knife. It has a hook on it and you pull, not press. Widely available. For us, the circular saw sounds like a better idea.

Jeff

I vote the circular saw option, with an old, no-good blade, if you have one. If your circular saw is not cheap and you hate to use it for that job, go to the pawn shop and get a cheapie.

In the absence of a hawk-bill, the circular saw would do it. Set the depth to slightly less than the piece of plywood underneath, protecting the drip-edge.

rote:

What plywood and what drip edge? The roof shingles should overhang the drip edge by an absolute minimum of 1/2", 3/4" preferred. I understand the concern about not cutting into anything else but shingles, but plywood (sheathing) and drip edge are not in harm's way. If you're talking about using a piece of plywood underneath the shingles to protect something, there's nothing to protect - they're supposed to be hanging in free air. Unless the shingles are resting on the gutter nails/screws, or the gutters are hung by straps, the circular saw can cut through both layers of shingles in one pass, except right into a valley. The valley will require some hand cutting with a hook blade utility knife. A hawkbill knife is not nearly as good as a hook blade utility knife for cutting in place roof shingles. A hawkbill is fine for scoring a shingle while it's loose.

On 3/22/2011 5:01 PM Jeff Thies spake thus:

I thought that's what he meant by "hawk-bill knife". Not familiar with that term, though. Izzat what roofers call that little blade on the back of their roofing hatchets?

By the way, I've got one of those, and used it the last time I did a roofing job (very small one). Love those pull-cut blades.

I would say a hawk-bill knife is a laminate or carpet blade. I am guessing this is a standard asphalt shingle. A hook blade cutting from underneath would be my suggestion. Why the overhang? The shingles should only be to the edge of the drip edge. Or did they forget to install that too?

I think they used to call 'em linoleum knives.

Correct.

No room. I'd tear my hands to shreds.

Drip edge was in place.

Was in the OP:

They ripped me off. Avoid 'em if ya can, but if ya gotta deal with loose roofers, watch 'em like a hawk.

I guess it's the circ. saw. Gonna be a bitch ...

Thanks to all.

Ten more years & you 'll need to replace those shingles !! You waited 15 why worry now????????????? Jr

I'm not either. What I meant was these:

Jeff

Izzat what roofers call that little blade on the back

Try a composite blade for steel. The lack of teeth should help avoid ripping the shingles to shreads.

Learn to follow threads. I was not responding to your post, but David's.

Don't dread things that don't require it. It's really not a big deal. The main issue is safety, so ladders with ladder jacks and planks, or something similar, is the way to go. The saw blade will only be exposed for roughly a 3/4" depth of cut, which minimizes a lot of the more grievous danger. Just go at a comfortable rate and let the saw do the work. Don't try to push it to make it go faster. That's how injuries and damage occur.

Have you ever used one of those blades to cut roof shingles with a circular saw? I'm guessing you haven't. Without teeth, same as with too many teeth, the shingles melt and bind the blade. The teeth don't rip shingles - moving the saw too quickly rips shingles. The OP will be trying to follow a chalk line from an awkward position - he certainly won't be moving the saw quickly.

Here's an 'outside the box' technique that might work (haven't tried it yet but maybe later): Put a sturdy support under the shingle and press hard with a pizza wheel as follow your chalk line. The thin circular blade should be fairly self cleaning and if you warm the shingles well with a heat gun the job ought to go fairly quickly. Amazon has pizza wheels if you don't know what they look like. This would have the advantage of avoiding cold splintering of the old shingles with toothed saw or similar. If you value your happy home don't try one from SWMBO's kitchen tool set.

Joe

Learn to get over it.

Jeff

Whatta larf. An old shingle talking like he can get 15 yr-old trim.

nb

You don't want cold/freezing as the shingles are more likely to crack while you're mucking about with them, and you don't want hot/direct sun as the shingles might get scuffed up more with the circular saw base running over them - plus it's no fun working on a roof when the sweat is running into your eyes. So mid-range temps - 50s, 60s, 70s.

One old junk ladder is all I got.

I'll keep it in mind.

I drug a circ. saw up there today just to size it up. If I can fashion a guide to keep the blade a uniform distance from the edge of the gutter, it might work.

There's maybe 8 gutter mount struts holding the gutter up. Have to remove or stop, lift saw, restart 8 times.

I popped a fine-tooth 'cip saw blade in and tested. Jammed the teeth with asphalt muy pronto.

Would you attempt to do the deed on a hot, sunny day with shingles softened, or on a normal/chilly day?

Thanks, Willie

Keep you hips between the rails. You're looking at doing no more than a yard before moving your ladder.

Snap a chalk line on it. It's worth buying one if you don't have one.

If you're cutting an inch or less off the roof edge and set you blade just deep enough, you shouldn't hit any hangers.

Rough blade should work better, but you need to start moving in slowly with full rpm. I haven't done this, but I'd try my jigsaw with a rough blade first. Lighter and easier to control. Cheaper blades too. You'd have to use a knife at the hangers. Nobody will notice. If somebody says anything tell them to stay off your roof.

You want just right. Not too hot, not too cold. Just right.

--Vic