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Discussion Starter #1
Hello,
When is it time to consider having a tar/asphalt roof ripped off down to the boards? I checked the thickness of the roof and it is about 1/2 thick in the one spot I checked. In Philadelphia, Pa. the roofers will lay down new asphalt paper over the old roof and cover it with hot tar and call it a new roof. Although this sounds a bit misleading but a lot of the local roofers are doing it. Of course it is much more cost involved to rip off the roof. Some roofers actually prefer to stay away from ripping off the roof. Any comments?
 

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Discussion Starter #3
Grumpy,
That was my first post ever on the roofing section. You have me mistaken for someone else. I will contact you on the chat forum.
 

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Grumpy,
I just tried to get into the chat forum and all I get is a white blank screen. I placed my user name in the box and left out the password because the instructions said it was not needed unless I was logging on as a moderator.
 

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The roof can be thicker in some areas, than others. You could have tapered insulation under the roofing to increase roof slopes.

What you described, by laying some new roofing over the old, is what I call a resurfacing. It will add life to the roof but isn't the best method of roofing IMO. I feel you get a better product when you tear off.
 

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catalfanoc
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I do roofing in philadelphia, We call what you are talking about a reroof. The reason alot of roofers don't want to rip those roofs off is because most of them have pitch under it which is what they used to use to glue the roofs down and it is a nasty chemical makes your skin burn. you get alot better job if you rip off the roof but the cost is over double.
 

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They used to call that a 'hotmop' down here. Mop hot tar, set the felt into it and mop again. On residential they would add gravel to the final coat and paint. SOB to tear off.
 

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Teetor, it's still called hot mop. It's also called Built up or BUR. They added the gravel to commercial as well.

BUR is going the way of the dino (LOL it's actually made from Dino, so that's a funny joke). There are so many new systems that asphalt is losing market share every year. Asphalt based systems are still dominant in the low slope market though, but slipping.
 

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I notice now that they nail the felt and mop over it. It works until we get one of our summer wind storms then it all comes off in one piece. We found the one to my bro-in-laws office in a parking lot 2 blocks away.
 

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They nail the first layer of felt to capture all that tar that likes to leak through the board and into the attic/crawl space. In chicago lofts the yuppies like to remove the ceilings and use the bottom T&G roof deck boards as their ceilings.

I laugh when ever I see tar leaking through.

BTW button head nails properly installed should be adequate to hold the BUR roof to the building. Staples or typical roofing nails probably wouldn't hold up in a hurricane.
 

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The place was built in the late 50's-early 60's, tabbed roofing nails 6 on perimeter, 12 in the field. Came off of there like a ripe banana peel.
 

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OK.

1. Pitch is not what is used to glue the roof down. It is the waterproofing component in a coal tar built-up roof, with felt being the reinforcment.

2. We will nail a base over a wood deck for a couple of reasons....A.like Grumpy said....B. so that you do not mop directly to the wood deck, making future removal next to impossible without removing said deck

3. Button cap nails are not for use in hot applications (liquid or torch). That is if you're talking plasticcaps. Steel caps are good

4. The gravel ballast is a ballast, mainly, but does do some UV reflecting. 400 pounds per square to hold the roof down

5. Built ups may or may not be on the way out. Jacklegs with no safety program in place are the main culprit, as it is dangerous stuff to work with, and many accidents have raised insurance premiums for this type of work.

6. BUR is one of the toughest roofs you can buy...the overlapping plies and sheer thickness makes it a good choice if you can find the right applicator.

7. You should never need tar paper in a built up roof, unless it is used as the slip sheet or to contain the hot.

8. Anyone that doesnt want to tear it off just doesnt want to. It is hard work, and Americans do not want to work hard anymore. Tear off will usually add 50% to a re-roof bid (if it isnt outrageously thick) which will result in 1/3 of the final figure.

I am starting a ten roof tar and gravel project this week. About two hundred squares total.
 

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Grumpy said:
BUR is going the way of the dino (LOL it's actually made from Dino, so that's a funny joke). There are so many new systems that asphalt is losing market share every year. Asphalt based systems are still dominant in the low slope market though, but slipping.
I grew up with the kettle smoking away at night in the driveway. I will admit, it doesn't smoke as much as it used to. For smaller low slope jobs, I've gone almost exclusively with self adhered mineral surface. Its clean, and you don't have to use slop sheets, granules, the kettle, mop carts,a bunch of grunts,... well, you get my gist.


Best regards
 

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Does it stay put at 200 MPH? That's my new criteria although a really good one can top 240.
 

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Doofus, the flat roof on my florida room was done the old way and survived 157 MPH. I'm beginning to question if you can meet their quality with more modern materials and techniques. I provide statistics and you reply with flippant answers, you are low on the credibility poll.
 

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I think he was being funny, Teetor. I do not know that anyone would guarantee those speeds, Teetor. MAybe with a double gravel coat, but still marginal.
 

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The older that I get, the more that I realise that progress does not mean moving forward.
This place was built on a barrier island in 1876 and suffered less damage than my house that is 2 miles inland. The storms also trashed modern multi-million dollar homes.
See the old place here http://iml.jou.ufl.edu/projects/Fall03/Stanton/refuge.html
Note that the roof is still on.
 

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Greetings, Mr. Teetteebuilt-

If you can spare the time away from the- "Gee, I wish I looked Like Johnny Depp" forum's moderator duties, perhaps you might answer this simple question- "Have you ever done any hot work?" It is important to the audience in that; without firsthand experience, you are in no position to dispense judgement on other's comments, flippant or factual. Having roofed side by side with Mr. Doofus Emeritus, I can assure those who know what a hot roofer is, and is he is. AS far as statisics are concerned, so what? Each roof is an individual case unto itself. For credibility reference, consider this: I recently attended a discourse on the effects of wind uplift relative to roofing AS affected by last year's hurricane roster that ganged up on the Southeastern U.S.. Note: This same symposium will be presented at the upcoming WSRCA Convention in Lost Wages, Nevada. Anyways, these gentlemen's multiple site surveys of damaged-to-non-damaged by wind roof systems revealed a common thread of symptomatic failure causes. The most prevalent being: the lack of proper attatchment for perimeter edge flashings. The phenomena of differential atmospheric pressures generated by wind AS it encounters a building's edge is translated into effects on a roofing system's ability to withstand, or surrender to extreme winds. By and large, a common thread was found to be a lack of fastener securement for edging, whether it was gravel stop, shingle nosing, or wall coping. The use of a continuous cleat helps, but even a simple nailed on gravel stop can survive if pre-hand crimped by the hot crew detail guy, and nailed at say a 3" staggered pattern. If'n the edge can catch the wind, it shall. Coupled with a vortex of roiling displaced airstream generating a negative pressure just behind the windward edge, a tremendous amount of force to peel is exerted. Now here's a factoid for ya' to ponder. Smooth surfaced flat roof systems; single ply, modified bitumen, or built up, seemed to fare worse than their traditional counterparts, built up tar and gravel roofing. It is another phenomena thusly by analogy: If one was to take, say a suction device mounted to the end of a stick, kinda like a plumber's helper thingie, and after Mr. Teeteepilt has a-licked the rim, smack it down onto a smooth surfaced roof, then pull upwards, low effort to overcome upward resistance will be immediately noticed. Conversely, if'n one was to attempt the same experiment onto a gravel surfaced built up roof, it might eventually become evident that one cannot gain a decent suckage on the roof because the rock won't letcha'. Same is the thwarting of surface ballast to Mr. Wind's prying attempts. However, if there's an opening edgewise to welcome in the wind, virtually no roofing system can withstand the invisible strength of moving air, field fasteners, substrate bonding, or weighty ballast all become missile and kites once the virginity of the barrier is breached.
By and large, the best roof system is the one that is installed AS per specifications by those who are qualified to do so, and have the 'Roofing Honor Code' of pride in workmanship, overseen by the trusty eye of the Doomsday 'What If-' supervisor.
AS far AS your palatial double wide's withstanding of 157 m.p.h., I'd have to say that you sure were lucky, seeing AS how none of the last hurricane's wind speed sustained gustage topped 140 m.p.h.. You and the entourage of cousins must lead a charmed life.

AS ever,

Your ol' pal,

Wally J. Corpse
 
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