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jally1

Roofing over concrete

jally
12 years ago

Hi, I have a very old concrete car-port hugging side of house, and its concrete roof has been doubling as a patio for decades.

Its approximate dimensions: 26' x 12.5'

Note: Chimney juts into the carport/patio at one point.

Due to its crumbling condition and leaking into the inside of carport, a mason is doing preliminary repair work as follows:

Digging down along side of carport

Cleaning cracks on patio/roof

Bonding agent on east-wall & rear wall

Applying stucco with sponge finish on walls

Filling cracks & corner of roof w/cement

Brushing off loose chippings on carport ceiling

The lowest-cost next step (per the mason) would be to apply rubber roll + torching, to waterproof the carport. (not sure whether its necessary to apply urethane prior to the rubber, or if the rubber suffices.

I only use the patio very seldom, to access the back yard, and could care less whether it looks "pretty" or not, since the house may possibly be torn down in a few years, due to new housing construction throughout the area.

What I'd appreciate, is if someone here knows what would be a fair estimate for rubber-roll +torch roofing per above dimensions (with preliminary power washing and/or whatever other preliminaries are advisable.

Thanks!

Comments (7)

  • brickeyee
    12 years ago

    EPDM has a much longer life than torch down bitumen.

    you should easily be able to get a factory seamed piece of EPDM to cover the entire roof with a single piece with no field seams.

    If you want to us it as a patio build wooden framing that rests on the EPDM for walking (think of fancy pallets).

    you can even use the wood to ballast the EPDM.

  • jally
    Original Author
    12 years ago

    Thanks brickeyee!

    Some questions:

    (1) Which option should cost less, EPDM or torched rolls, and approx. what should each cost? I'm wondering if EDPM is so readily available here. The guy at Home Depot didn't mention it to me, and roofers may prefer more available options.

    As I said, I seldom use it for walking on, so I'm not all that concerned about setting up pallets
    ...(except perhaps as a pathway toward steps down to back yard... then again, I've yet to hear what roofers would tell me.

    (2) Could EPDM stay put without ballasting?

    (3) Above all [strongly mulling over]... would the roofer agree to go the EPDM route, or would he get mad if I presume to give him suggestions.

    The reason I ask, is because what I didn't anticipate at the time of my original post, is that just within this past hour, the mason referred me to someone he said is very good, and he strongly advised me not to give the guy any instructions, but rather hear what he has to say, since they don't like being told how to do their job.

    Note that the mason is a top guy referred by top authorities locally, which is why i'd hope that anyone he refers would recommend the best option tailored to my circumstances.

    I'm just wanting an idea what these options should cost for above dimensions.

  • brickeyee
    12 years ago

    Home depot is about the worst place to even think about roofing materials.

    Bitumen torch down may have a lower initial cost, but will not last nearly as long as EPDM.

    Firestone is th major EPDM manufacturer but they have no real interest in the residential market.

    Why bother when every large shopping center and commercial building is already using your product?).

    There are a numerous of on line sources for factory seamed EPDM pieces, up to very large size pieces.

    No matter what you do to concrete it is not going to stop all water.
    The best you can do is stop major gushing leaks.

    Since no one knows where "here" is no one can tell you what is available locally.

    EPDM can be ballasted down with gravel (though an extra layer of non-woven material is required if there are any sharp edges in the stone) or even glued down (how it is done on large buildings).

    Or you can use bitumen torch down and replace it every 10 years or so when it starts to crack and leak at the seams

  • jally
    Original Author
    12 years ago

    Thanks!

  • jally
    Original Author
    12 years ago

    P.S. brickeyee, I sent PM followups.

  • jally
    Original Author
    11 years ago

    Urgent followup re: Roof (done today)
    (please refer to the 2 photo's further down)

    Guess what, the guy did actually agree to apply a 10' roll plus a 3' roll.

    Because the 10' was the maximum size he could get locally, and he preferred cutting the notches himself, which was why he preferred local. The notches were necessary to hug the wrought iron rails running every few feet at patio perimeter.

    The 3-footer is running alongside house wall (see my pics), and it overlaps the 10-footer that's spread across the remainder of patio until it finally overlaps the patio edge.

    So here's the problem which had developed:

    Perhaps due to weather being in the 50's with wind blowing alot, the large piece of rubber failed to stick to the concrete. And some parts of it has developed large bubbles, sorta like when you apply contact paper, except these bubbles are much larger.

    Mind you, the concrete had been pressure washed this past Thursday thoroughly.

    Also, today, despite the 50 degree wind, the sun was shining plenty on the patio which is at east side of house, and the job was done in the morning hours when sun is at east & southeast.

    Not only that, the guy spent hours at 2 stores, both of whom told him the exact same thing. Their instructions were, that once the concrete of patio is dried out for a few days after pressure washing, he then electronically mixes the yellow sticky Toxic goo which comes with the 10' wide sheeting, and applies it to the patio top, and then it should stick. He specifically asked both of them whether any primer is necessary first, and they said no.

    The shop guys never told him that it wouldn't stick to concrete. He was very upset, as this never happened to him before (he's been a constructions specialist for decades).

    Is there any remedy?
    Please see pics below for clarification.

    I'm having some deja vu, reminded of the time when someone sanded, then applied toxic-smelling polyurethane to one of my hardwood floors, and the stuff never dried because he failed to mix it with a paddle, rather just shook it up & down. It need to be scraped off, then re-sanded & re-done at huge cost & headache.

    The difference is, that this guy did everything according to instructions. The only possibility is that either the weather was too windy, or else the rubber & bonding wasn't meant for this concrete.

  • energy_rater_la
    11 years ago

    ok, we know it smells bad, but it is outside
    and not toxic like as if it were in your house.

    what does the contractor say about the
    areas in the pics above?
    has he been out to see the job since appling
    the material?

    as he is the one responsible, it would be
    the first course of action to get his response.

    best of luck.