Roofing Question

SandEagle

Lifer
Aug 4, 2007
16,809
13
0
i'm looking at getting my entire roof replaced. i had a contractor say that it's cheaper to just put a second layer of shingles on top of the existing one. is he being a slacker? i don't see how he can inspect or replace the plywood by doing this? would u suggest ripping off old shingles vs. adding it as another layer?

thanks
 

Kirby

Lifer
Apr 10, 2006
12,028
2
0
Has the roof been damaged? If so, definately take a look at the plywood.
 

SandEagle

Lifer
Aug 4, 2007
16,809
13
0
Originally posted by: nkgreen
Has the roof been damaged? If so, definately take a look at the plywood.

some wind damage...and missing shingles...thats all i can tell

home is 15 years old
 

iamwiz82

Lifer
Jan 10, 2001
30,772
13
81
It's not against code but I am not a fan of it. You also will have a shorter life on your second layer. Plus with a tear off you can replace any bad decking.
 
Jan 18, 2001
14,465
1
0
Originally posted by: iamwiz82
It's not against code but I am not a fan of it. You also will have a shorter life on your second layer. Plus with a tear off you can replace any bad decking.

I wouldn't expect any bad decking on a 15 year old house.
 

iamwiz82

Lifer
Jan 10, 2001
30,772
13
81
Originally posted by: HomeBrewerDude
Originally posted by: iamwiz82
It's not against code but I am not a fan of it. You also will have a shorter life on your second layer. Plus with a tear off you can replace any bad decking.

I wouldn't expect any bad decking on a 15 year old house.

Missing shingles makes me thing that water has probably gotten through. I'd bet there is a bit.

Plus, 2 layers of shingles would instantly knock down the value of the house, in my opinion. That is something that would definately be listed in a home inspection.
 

Balr0g

Senior member
Oct 16, 2008
222
0
0
I don't think you should ever put a second layer over the top of existing.

Also - if you really are just using shingles, it would be very very easy to replace them yourself. Tearing them off is easy. You might need some new flashing here and there after you're done - no biggie.

After they are off you can inspect the ply and see if any needs replacing. Even replacing the ply is not hard and easily done yourself. I don't think you should really have to hire anyone. Not the best time of the year to be doing this though - best done in the summer so the heat can melt the tar on the shingles and create that barrier so water can't get through.
 

walrus

Golden Member
Dec 18, 2000
1,544
13
81
Sounds like you have an honest contractor, he's just trying to save you money. Someday, after 2 or 3 reshingle jobs you'll need to remove all of them.
 

pstylesss

Platinum Member
Mar 21, 2007
2,914
0
0
Originally posted by: walrus
Sounds like you have an honest contractor, he's just trying to save you money. Someday, after 2 or 3 reshingle jobs you'll need to remove all of them.

This is true. You can safely go up to 3 layers. Don't do any more than that. 2 layers is no problem. And who cares if it's listed on the home inspection? Any inspector with a brain will just note it as a fact and won't have a problem with it.
 

Capt Caveman

Lifer
Jan 30, 2005
34,543
651
126
Originally posted by: iamwiz82
Originally posted by: HomeBrewerDude
Originally posted by: iamwiz82
It's not against code but I am not a fan of it. You also will have a shorter life on your second layer. Plus with a tear off you can replace any bad decking.

I wouldn't expect any bad decking on a 15 year old house.

Missing shingles makes me thing that water has probably gotten through. I'd bet there is a bit.

Plus, 2 layers of shingles would instantly knock down the value of the house, in my opinion. That is something that would definately be listed in a home inspection.

If it's accessible, inspecting the roof from the attic will determine if there's any water damage. If there is no damage, shingle over the existing layer is perfectly fine. Will save you the money of having the existing roof removed and makes no difference when you try to sell. The only issue if you were to sell if the top layer needed to be replaced. The new home owner would have to remove both layers to reroof instead if there was just a single layer and then could just shingle over the existing layer.

If you live in an area that gets snow, you may want to have an ice shield put on the first 3-4' from the edge of your roof which will require removal of the existing layer on those areas.
 

SandEagle

Lifer
Aug 4, 2007
16,809
13
0
Originally posted by: Balr0g
I don't think you should ever put a second layer over the top of existing.

Also - if you really are just using shingles, it would be very very easy to replace them yourself. Tearing them off is easy. You might need some new flashing here and there after you're done - no biggie.

After they are off you can inspect the ply and see if any needs replacing. Even replacing the ply is not hard and easily done yourself. I don't think you should really have to hire anyone. Not the best time of the year to be doing this though - best done in the summer so the heat can melt the tar on the shingles and create that barrier so water can't get through.



good point. thanks. the contractor quoted me $4800 to do the work. he wants a couple thousand more on top of this if he tears the first layer off. that seems kinda steep, but my insurance is going to cover it so i'm not too worried about that.

also, i didn't think about doing it in the summer. maybe i'll just get it done next year.. who knows. i think then i'll try to rip it off myself; even if i screw up it's getting replaced anyway :)
 

Balr0g

Senior member
Oct 16, 2008
222
0
0
Originally posted by: rrahman1
Originally posted by: Balr0g
I don't think you should ever put a second layer over the top of existing.

Also - if you really are just using shingles, it would be very very easy to replace them yourself. Tearing them off is easy. You might need some new flashing here and there after you're done - no biggie.

After they are off you can inspect the ply and see if any needs replacing. Even replacing the ply is not hard and easily done yourself. I don't think you should really have to hire anyone. Not the best time of the year to be doing this though - best done in the summer so the heat can melt the tar on the shingles and create that barrier so water can't get through.



good point. thanks. the contractor quoted me $4800 to do the work. he wants a couple thousand more on top of this if he tears the first layer off. that seems kinda steep, but my insurance is going to cover it so i'm not too worried about that.

also, i didn't think about doing it in the summer. maybe i'll just get it done next year.. who knows. i think then i'll try to rip it off myself; even if i screw up it's getting replaced anyway :)

Just be sure to store any shingles in a cool(er) place like inside a shed so no direct sunlight hits them. They are not fun to pull apart if they sit out on hot cement in the sunlight. Just take out a couple packets at a time as needed. This is if you do it yourself :)

 

Marinski

Golden Member
Apr 5, 2006
1,051
0
0
classicboxingfights.blogspot.com
Originally posted by: Balr0g
Originally posted by: rrahman1
Originally posted by: Balr0g
I don't think you should ever put a second layer over the top of existing.

Also - if you really are just using shingles, it would be very very easy to replace them yourself. Tearing them off is easy. You might need some new flashing here and there after you're done - no biggie.

After they are off you can inspect the ply and see if any needs replacing. Even replacing the ply is not hard and easily done yourself. I don't think you should really have to hire anyone. Not the best time of the year to be doing this though - best done in the summer so the heat can melt the tar on the shingles and create that barrier so water can't get through.



good point. thanks. the contractor quoted me $4800 to do the work. he wants a couple thousand more on top of this if he tears the first layer off. that seems kinda steep, but my insurance is going to cover it so i'm not too worried about that.

also, i didn't think about doing it in the summer. maybe i'll just get it done next year.. who knows. i think then i'll try to rip it off myself; even if i screw up it's getting replaced anyway :)

Just be sure to store any shingles in a cool(er) place like inside a shed so no direct sunlight hits them. They are not fun to pull apart if they sit out on hot cement in the sunlight. Just take out a couple packets at a time as needed. This is if you do it yourself :)

But they're easier to cut when hot and less likely to split.
 

Ultralight

Senior member
Jul 11, 2004
990
1
76
I have worked in construction for a number years, including roofing. My father and brother are still in the business. They will tell you to not go over an old roof. You'll want the old torn off and all mew put on.
 

waffleironhead

Diamond Member
Aug 10, 2005
7,128
625
136
There is no reason to remove the existing layer. The added weight to the roof is minor for a newly constructed house. If this were an older home with 2x4 rafters i would recommend tearing off the initial layer. As long as code allows, which it seems to since he quoted 2 different prices. The layer over is way fast as they already have lines set to go off of to place the new layer. It goes quicker(less time=less cost.

But if insurance is paying for it, just have them tear it all off.
 

LeadMagnet

Platinum Member
Mar 26, 2003
2,348
0
0
a second layer is normal, a third is rare if not illegal. Only 15yrs the decking should be fine.
 

Balr0g

Senior member
Oct 16, 2008
222
0
0
Originally posted by: Marinski
Originally posted by: Balr0g
Originally posted by: rrahman1
Originally posted by: Balr0g
I don't think you should ever put a second layer over the top of existing.

Also - if you really are just using shingles, it would be very very easy to replace them yourself. Tearing them off is easy. You might need some new flashing here and there after you're done - no biggie.

After they are off you can inspect the ply and see if any needs replacing. Even replacing the ply is not hard and easily done yourself. I don't think you should really have to hire anyone. Not the best time of the year to be doing this though - best done in the summer so the heat can melt the tar on the shingles and create that barrier so water can't get through.



good point. thanks. the contractor quoted me $4800 to do the work. he wants a couple thousand more on top of this if he tears the first layer off. that seems kinda steep, but my insurance is going to cover it so i'm not too worried about that.

also, i didn't think about doing it in the summer. maybe i'll just get it done next year.. who knows. i think then i'll try to rip it off myself; even if i screw up it's getting replaced anyway :)

Just be sure to store any shingles in a cool(er) place like inside a shed so no direct sunlight hits them. They are not fun to pull apart if they sit out on hot cement in the sunlight. Just take out a couple packets at a time as needed. This is if you do it yourself :)

But they're easier to cut when hot and less likely to split.

Hot is one thing - when they end up melted together and they rip when you try to get them apart - that is bad.
 

rise

Diamond Member
Dec 13, 2004
9,116
46
91
Originally posted by: walrus
Sounds like you have an honest contractor, he's just trying to save you money. Someday, after 2 or 3 reshingle jobs you'll need to remove all of them.

 

SphinxnihpS

Diamond Member
Feb 17, 2005
8,368
25
91
Whoever said tearing shingles off a roof is not hard has never done it.

It is important to realize that it is the felt paper under the shingles that prevents water intrusion. The shingles just protect the paper from the sun and wind.

If you do go with a second layer, have them put on the 30lb felt paper instead of the 15lb. The reason being that the paper is not going to lie perfectly flat, and every time the roof is walked, the new paper layers tears on the singles beneath it. The 30lb paper will hold up much better in this situation and costs only nominally more. Insist.
 

waffleironhead

Diamond Member
Aug 10, 2005
7,128
625
136
Originally posted by: SphinxnihpS
Whoever said tearing shingles off a roof is not hard has never done it.

It is important to realize that it is the felt paper under the shingles that prevents water intrusion. The shingles just protect the paper from the sun and wind.

If you do go with a second layer, have them put on the 30lb felt paper instead of the 15lb. The reason being that the paper is not going to lie perfectly flat, and every time the roof is walked, the new paper layers tears on the singles beneath it. The 30lb paper will hold up much better in this situation and costs only nominally more. Insist.

HUH? WHAT?, The shingles are the first line of defense to stop water intrusion. They do more than just protect the felt. The felt is only there to act as a vapor barrier not as a water barrier.
 

BoomerD

No Lifer
Feb 26, 2006
66,718
15,117
146
Since you say your insurance company is paying for the repair, get it done right the first time.

IMO, while you CAN shingle over old shingles, it's never a good policy to do so. Only by removing the old shingles and felt can you be sure there's no damage to the roof sheets. (yes, you MAY be able to inspect them from the inside of the attic, but from the outside, you get a MUCH better idea of any damage.)

Sounds like you need to get estimates from more than one licensed roofing company.
Make sure any roofer you use will guarantee, not only the product, but his work...and be sure the roofing manufacturer will warranty installation over old shingles if you go that way.
 

edro

Lifer
Apr 5, 2002
24,326
68
91
1. Give your insurance the quote for a complete job.
2. Get the check from your insurance company.
3. Have the contractor do a new layer only.
4. ...
5. Profit.