roofing question

**SDHNTR** · 08-01-2009, 08:12 AM

I need to know the pros and cons of laying a new roof over existing shingles vs a whole tear off then re roof. The cost difference is substantial.

My house used to have one of those asphalt and gravel rock roofs. The rocks were removed, felt laid down and then composite shingles on top. So depending on how you look at it, I have one or two existing layers, but only one layer of actual shingles.

I'm trying to figure out what to do. Either I pay $1500-2000 to have the roofing guys tear it off or I do it myself with some cheap labor. I don't really have the time and by the time I hire some guys and get a dumpster I'm looking at $1000 or so. The DIY savings is probably not worth it.

Realize too that this is not my dream home. I don't plan on living in it more than another 6 or 7 years tops.

Anyone been faced with this before? Tear off or lay new shingles over?

**easymoney** · 08-01-2009, 08:22 AM

IMHO, it is always best to strip off old and apply new felt and shingles. But, if the old is is good shape and you plan on moving on, the take the short cut.
Remember, you get what you pay for.

**slanttop357** · 08-01-2009, 08:24 AM

Originally Posted by SDHNTR

I need to know the pros and cons of laying a new roof over existing shingles vs a whole tear off then re roof. The cost difference is substantial.

My house used to have one of those asphalt and gravel rock roofs. The rocks were removed, felt laid down and then composite shingles on top. So depending on how you look at it, I have one or two existing layers, but only one layer of actual shingles.

I'm trying to figure out what to do. Either I pay $1500-2000 to have the roofing guys tear it off or I do it myself with some cheap labor. I don't really have the time and by the time I hire some guys and get a dumpster I'm looking at $1000 or so. The DIY savings is probably not worth it.

Realize too that this is not my dream home. I don't plan on living in it more than another 6 or 7 years tops.

Anyone been faced with this before? Tear off or lay new shingles over?

Hi SDHNTR i forgot where or when i seen or read this artical about a new product someone invented that you spray a coat of this stuff on your existing roof they say it seals and reflects up to 30per cent of the suns rays or something like that, good luck with the roof

**sancho** · 08-01-2009, 08:36 AM

from what i hear, there is no ill affect of leaving one (i have seen two) layers of existing roof underneath the new system. the only downside i can see from an engineering standpoint is the added weight. in a seismic event, you will have one more lining of shingles up top. oh, when you reach the city's code limit (my city allows two layer beneath a third), you will have to pay much more to dispose of all those layers.

let us know what you decide. my house has two layers...i bought it that way, so when i redo my roof, i will strip it down to wood. i have some time, thank goodness.

**SDHNTR** · 08-01-2009, 10:19 AM

Old roof is in pretty good shape, no leaks at all. It's a 20 yr roof done in 1987 so it's past time and I want to address it before it becomes a real problem. Especially with a baby coming in Oct. I don't want to deal with a leaking roof, a pissed off wife and a crying baby this Winter. I've also hated the look of the roof ever since we moved in. It just cheapo 3 tab, light grey, comp shingles. It looks cheap and I don't like it.

**Marty** · 08-01-2009, 10:26 AM

I think there are two other concerns:
First, a poor job installing a new roof can cause leaks faster than an aged roof. Second, what does your local building code require? You said the first roof was rock over tar. That roof is usually reserved for a low-pitch, or flat-pitch roof. Shingles are not always approved for low to flat-pitch roofing.

**SDHNTR** · 08-01-2009, 10:47 AM

Code is not an issue. Code says up to 3 layers of shingles. I had a licensed roofer look at it. Pitch is not that steep but far from flat.

**irishhunter** · 08-01-2009, 06:46 PM

My preference has always been to strip back to bare wood if you can . The drip edge metal and eaves always suffer worse longterm damage even if the roof layers are replaced and fixing raftertails and eaves is a pain. The shingles laydown better when on a good substrate and you get better nail holding power in wind prone areas. strip it . refelt it and new roof you will be better off imho if the roof leaks the cheaper fix will be an expensive one

**Birddog3** · 08-01-2009, 07:14 PM

I agree with Irishhunter......I had a new roof put on this Spring. I didn't know it, but I had 3 layers of roofing materials. Wood over composite over wood. The roofer said he had never seen that before. Usually it's wood over composite or the other way around. As I understand it, the waterproofing comes from the paper not the outer materials. So it would be important to replace the paper. Another factor to consider is with only layer, your house will breathe better. Which will allow the heat from the attic to escape better and make the house cooler. This was the case with my house.

**SDHNTR** · 08-02-2009, 06:55 AM

I don't live in a windy, nor hot area and #15 felt will be layed down first. Does that change anything?

**crustyde** · 08-04-2009, 06:17 PM

If you are just taking the shingles off, two laborers should be able to tare off a 25 squares in a day, with a dumpster on sight and in throwing reach of the roof ($500 total.) If you want to take it all off it can be a pain. Built up roofs can be a nightmare. If the tar was mopped plan on replacing the sheathing also. If it has a nailed base it will be easier. As far as pitch, city or county building will govern it, but typically you do not want comp. on 2.5/12 or less. Code may be alright with 3 layers but also call your insurance company and possibly a realtor. Many home insurance companies do not like to see more than two layers and it can pose a problem if you are audited or when you try to sell the house. If you plan on moving in 6-7 years you may find trouble with the buyers insurance company excepting three layers. In which case you will have to tare the new roof off and replace it.