? for any shingle roofing contractors

[Gale Hawkins]

It has been a while since I have been involved in reroofing any three tab roofs and some of the practices I am hearing reported by bidders on our church roof is making me question my current thinking.

Our church has four layers of three tab singles with the bottom layer being 46 years old because I was 13 when it was built. The advice we are hearing is to tear off two layers and reroof.

I have stripped down to the deck before but I have never removed some layers and left others. The first roof put on was with very low priced shingles. After prying off 2 top layers I would expect the remaining old cheap singles and will no longer make good under layment.

Question: Is it an accepted practice to remove a 2 layers of old 4 layer roof and use the two oldest ones for the base of the new three tap shingles?

There are no building codes I know about in our county and no building inspectors. Where there are codes I have read that they vary from 1-3 layers being permitted.

 

[CurlyDave]

Not a roofing contractor, but it sure sounds like a bad idea to me.

I have torn off a few roofs, and I don't think it would be possible to take off the top two layers of shingles without damaging and in some places removing the first layer.

One thing for sure about the proposed method, you will not discover any dry rot if you have some...

 

[Duffster]

It has been a while since I have been involved in reroofing any three tab roofs and some of the practices I am hearing reported by bidders on our church roof is making me question my current thinking.

Our church has four layers of three tab singles with the bottom layer being 46 years old because I was 13 when it was built. The advice we are hearing is to tear off two layers and reroof.

I have stripped down to the deck before but I have never removed some layers and left others. The first roof put on was with very low priced shingles. After prying off 2 top layers I would expect the remaining old cheap singles and will no longer make good under layment.

Question: Is it an accepted practice to remove a 2 layers of old 4 layer roof and use the two oldest ones for the base of the new three tap shingles?

There are no building codes I know about in our county and no building inspectors. Where there are codes I have read that they vary from 1-3 layers being permitted.

That idea is absurd. :confused2:

Have it stripped down to the sheeting and use a higher quality shingle, or better yet steel.

If this roof had been done right in the past you would be looking at doing the third roof instead of the fifth.

 

[magicheater]

I did a lot of roofs when I was younger. A complete tear off is the correct way to go along with a new layer of roofing felt. Applying shingles over an existing layer only shortens the life of the new layer and adds unwanted weight especially when dealing with snow loads. Shingles may not seal properly as well. There are many new metal roof products out that give the look of a shingled roof but way out last them. Pricier but consider it a lifetime roof.

 

[Mousefield]

Not a roofing contractor, but it sure sounds like a bad idea to me.

I have torn off a few roofs, and I don't think it would be possible to take off the top two layers of shingles without damaging and in some places removing the first layer.

One thing for sure about the proposed method, you will not discover any dry rot if you have some...

Same idea, remove all the layers and start fresh. Would be hard to get a nice flat roof with a couple of old layers as the base. I reroofed a couple of porches last year at our place and took off all the old stuff. That way I started with a nice flat roof.

 

[LeadPoison]

I am a roofing contractor and everyone here has the right idea. It's a commen sense thing. The best thing to do is tear off down to the deck and inspect it for any signs of rot. It is possible you may need to re-deck if the wood is at all spongy. Also you can get into a situation where there are so many nails holes in the deck that it compromises the integrity. Not common, but something to be aware of.

Just go back with a 30-year plus asphalt shingle. Don't get the plain 20 or 25-year stuff. It's crap. You can probably get away with just 15# felt.

Shop around for price. You should be able to get all the materials and be less than $80/square or cheaper for nails, felt, shingles, drip edge, vents, etc...

 

[Dmace]

In most places, especially up here in New England only 2 layers are permitted and any more is against building code. Not only is it a bad practice but the new shingles laid over the old will not perform or last as they should.

Plus, many people don't realize that many shingle manufacturer warranties are ONLY valid when installed on the roof sheathing and NOT valid if installed over another layer of shingles.

 

[irvingj]

Another thing to possibly consider-- up here, a membrane covering (Grace brand or similar) has become very popular; makes for a really complete moisture barrier.

I'm no roofer, but I'd have to agree with others here- rip off ALL the old stuff and start fresh, while checking the roof for rot. I had a bit of a surprise when I had mine done 2 years ago!

 

[Pops15]

Tear off all existing roofing!!!!!! I've torn off several roofs that had 5 layers and one that had 8 layers! The nails didn't even reach the sheathing. They were just nailed into the layers of shingles.
The reasons to tear off to the deck are.... you need to be able to inspect the sheathing and replace it if necessary, added layers of roof is more weight the roof has to carry thereby reducing the amount of snow load it can carry, and multiple layer roofs just don't look as good.
Use an ice & water barrier along the eaves, up the rake, and in the valleys. Use a good quality shingle underlayment. Some say 15# felt, other will say 30#. I suspect the 30# will perform better in regions with extreme heat. I've found here in the midwest that all else being equal hail damage with be less with 15# vs. 30#. It seems the 30# is cushier and gives more allowing hail to cause more damage. I haven't seen a QUALITY 3 tab shingle in 15 years. DO NOT USE 3 TABS!!!!!!! You'll just be wasting your money. Go with architectural shingles. Buy the best shingles you can afford. Spring for 40 or 45 year shingles if you can. It's money well spent. The most expensive part of a roof is the labor. It takes the same amount of labor to install 15 year shingles as it does 45 year shingles. The cheaper the shingles, the more expensive the roof becomes.
I agree that you should be getting ready for your 3rd roof instead of the 5th. Think what using cheap materials has really cost (2 roofs that shouldn't have been needed). Spring for quality materials this time. Also hire the best roofer you can find. Just about anyone can nail shingles down. That doesn't mean the roof will remain leak free for 40 years. Find a LOCAL roofer that's been in business a long time.

 

[PILOON]

INHO, Grace iceshield underlay is the way to go!
on the entire roof!
It self seals (nail holes) creates a total seal but wears poorly, and that is why you then need a shingle to cover it over.

The iceshield install is labor cheap, simply unroll and presto, done.

Then a regular 3 tab product that bascially is installed to prevent erosion of the grace product.

As to felt underlay, well on most that I have re roofed, the underlay is powder or at best small fragile pieces that do no good at all.
My belief is that the felt underlay was an attempt to even out dips and cracks in the old T & G rough decking used back then.
I notice that around these parts roofers use no underlay at all on sheeting type roof decks but do all edges, nooks and vallies with ice shield and from there I figure that the remaining areas are at minimal cost to completely iceshield for that additional protection.

I did one roof that leaked in the lower 3-4 ft due to poor ventilation and inadaquate insulation (cathedral ceiling), so I iceshielded about 12 of the lower footage.
It started leaking at 12 ft proving that total ice shield does in fact work.
Every roof since then was totally iceshielded that I did! (unless it was a well ventilated real attic with R40 insulation).