Better Option to Hot Tar Roofing?
BilljustBill
| Posted in Construction Techniques on
Patio has a 14 year old hot tar roof; no leaks. Need to update it. Slope of patio roof is a little more than a 1/12 while the ranch style roof is more of a 3/12….
If new 40 yr. Elk shingles are put on the house, what would you do for new roofing on the 16 x 44″ patio roof?
How much difference in cost between hot tar and what you are suggesting?
Thanks for your help and badly need information,
Bill
Edited 5/14/2008 12:09 am ET by BilljustBill
Replies
Bill my choices from best to least are:
EPDM roof
Torch Down
Hot Tar
EPDM is going to cost the most but very little chance of a leak. My farther inlaw put one on after dealing with hot tar for years that leaked some where every winter, been down 5 plus years no leaks any where. But then yours is only a patio so may want to check out torch down.
edit:
Bill 16x 44 inches or feet? Did not catch it till after I wrote my reply but looks like you are saying inches? If that is the case a roof that small has very little chance of ever leaking I would go with what is cheapest but best looking.
Wallyo
Edited 5/14/2008 12:23 am ET by wallyo
Wallyo,
The patio roof is 16' x 44', with 2x6's on 24" centers. Decking is 1/2. I also had coated it with the solar white sealant that required a special primer, but it only lasted less than 4 years.
Any idea what the cost comparison is between the hot tar and the EPDM? Any other links or websites would help, too.
Thank you for your help,
Bill
How many layers of BUR are on the roof now? The reason I'm asking is the weight factor and it may be possible to add another 2 plys of BUR on top of what's there and prolong it another 10 years.
To do EPDM, you'd need to tear off if you're maxed out on weight, although EPDM doesn't weigh much. If the roof's not overloaded, recovery board can be installed over the existing BUR and the EPDM glued to it. Some one way vents need to be installed to release any outgassing from the BUR.http://grantlogan.net/
But you all knew that. I detailed it extensively in my blog.
Have you looked at a self-adhering modified bitumen ? For this application you could get all the material you need to do it for a thousand bucks. Mule-hide makes a really good product and you can color match it to your shingled roof.
Naive but refreshing !
Edited 5/14/2008 7:39 am ET by woody1777
My own experience:
1. true rubber roof just sounds like it will do better if there is standing water. I have no experience with this, but you'd want longer life roofing to go with your shingles.
2. I used epdm roof, doing it myself and using its own adhesive. It's been 10 years. At about 7 years, some parts began to show granule deterioration and leaking between overlap joints. The roofing at the overlap joints began to split if squeezed out adhesive was left alone. No split if squeeze-out was scraped away. Do not overcoat with one of those roll-on "rubberized" roof paint. This kind of paint, I think, has worse effect on epdm roof. Definiitely use instructed material and adhesive for flashing and if you can afford it, check adhesive tape from Eternabond.com. I believe this tape will allow flashing in a worst possible situation.
3. I would remove all original roof down to plywood. Patio may not be constructed with big enough wood to hold all the weight. The roof I did had roll roofing, fiberboard, original hot tar roof and more fiberboard. At some parts all of this was soaked. If you remove to original condition, you may be able to restructure the slope of your roof as well for better drainage.
4. If only up-dating is the point, and if you can afford it, look into the cost for edge treatment. That is, copper for the flashing for edge, gravel-stops, etc, where it shows.
5. I'm not sure how you'd transition from roll roof to shingles. My guess would be epdm would go up the slope to about a foot. Ice shield? Then shingles. This is tricky area and be very sure about the construction method here.
6. Epdm would cost more but less trouble later. Well done hot tar has long life, but I can't imagine how the transition can be assured. If you're sure about tar roof you have, consider keeping it. Epdm would have to be replaced before the shingles. If you want to replace, I would seriously think about rubber roofing that you install with contact cement. Rubber has longer life. In any case, don't use fiberboard as backer board. I think fiberboard is just asking for trouble. I think there is foam board that you can use. Be there to check the material and installation and don't install epdm (glue down) in winter. Good luck.