| Author |
Message |
Peter E (Sdibaja)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 8:14 am: | |
Looking for wisdom and knowledge, I find lots of both here so here goes…
I work and live in San Diego, California and I also have a home in Baja, Mexico.
This regards the Baja home:
I have a roof top patio that is terracotta tile over concrete, on a wood frame building.
The original construction laid up hot tar, then the concrete, and then the tile.
It is L shaped, about 14’ x 6’ and 12’ x 20’
84 sq. ft. + 240 sq. ft. = 324 sq. ft. total
Of course, it leaks!
I believe the best fix is to remove the tile and lay a good flexible membrane over the concrete, then lay new tile.
The question is: what material to use and where do I get it?
Home Depot and Lowes is no help….
Transport from San Diego to Mexico is Not an issue.
Thanks, Peter Ehlert |
TWO DOGS
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 10:25 am: | |
Home depo has HEAVY plastic....I believe I'd do a double layer of it,then the tile...you say 'new' tile...do you have broken tile up there now ?? |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 12:16 pm: | |
Membranes will leak, like any plastic material, over time and use.
Why not a heavy coating of fiberglass and/or epoxy? You'd have
one helluva base for near anything. |
Ron Walker (Prevost82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 12:29 pm: | |
Hi Peter...
1-Does it have parapets around the perimeter of the roof?
2-Are there scuppers for draining the water off the roof?
3- Is there any slope on the roof , from the center to the outsides?
Your problem, is the concrete probably moves form heating and cooling and tears the "hot tar" or it was torn during concrete placement.
As you said strip off the existing tile roofing and install the following…..
There’s a product called torch-on, that is a membrane, so it won’t tear with the heating and cooling of the roof. You install it with a propane torch. If the house has parapets around the perimeter of the roof you have to run the torch-on up the parapet 6 to 8 inches and cut out where your scuppers are.
If you are going to use it as a deck you should lay down pressure treated 2x4 sleepers on the flat @ 3 ft on center, then install your 1x6 treated decking on top of the sleepers and fasten to the sleepers with 1 ½ lg screws. Don’t fasten the sleeper to the concrete or penetrate the torch-on with the deck screws.
Ron |
Dave Hartshorne (Yeeolde48)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 12:31 pm: | |
Peter, The large over the road trailer companies use a paint on rubber based product to seal the tops of their trailers, and I have seen it used on older RV's to seal leaking roofs. I have used it as a sealing membrane very successfully. You can brush it on as one thick coat, or as 2-3 thin coats, and can even set your tile layer directly onto it. Some of the truckers on line may be more familiar with it, but it dries very flexible and I have found it to be a lot more durable than a plastic membrane. If you paint a couple of layers then use the final coat to set your tile, you should get a very durable roof. |
Peter E (Sdibaja)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 2:01 pm: | |
Ron:
1-yes, there are parapets (yes, I will wrap up the walls)
2-yes, there are scuppers (they will be tied into the new mwmbrane)
3-yes, it slopes about 1" in 10'
I just did a search for "torch-on", but without more I get too many hits...
John: I am sure that any rigid treatment will crack and break... the hot tar did, I need an elastic membrane |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 2:14 pm: | |
Hummm.....
"a roof top patio that is terracotta tile over concrete, on a wood
frame building. The original construction laid up hot tar, then the
concrete, and then the tile."
""flexible"" - and - cement/tile
It doesn't really go together, does it?
If the underlayment is flexible, how is it going to keep the tiles
from moving and destroying the underlayment?
Most of the membrane coatings I've seen, are not to be used as
an underlayment for any type of finished surface; the coatings -are-
the finished surface... |
Ron Walker (Prevost82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 2:28 pm: | |
Hi Peter....You are right, any rigid treatment will crack and break... you need an elastic membrane, which Torch-on is.
all your "yes" answers are good...and this product will give you long life.
make sure you cut the membrane so it runs down the scupper a bit....also flashing maybe req'd around the top edge of the membrane and a cant strip where the roof meet the parapet, for a smooth transition, maybe req'd.
Torch-on....
manufacter ...IKO
product name ....Torch-Flex
this is just one manufacture...but there are others
I had to make a few calls on that one, LOL, all us designers spec it as torch-on...even the bldg supply guys didn't know the product name.
good luck
Ron
If you |
DAVIDHEAD
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 2:29 pm: | |
there is a product available for flat roofs .It is a rubber membrane .Go to rubber roof membranes on your search and you will find the product.It is used in Canada in many roof applications |
Ron Walker (Prevost82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 2:36 pm: | |
Hi David ...we are talking about the same thing...
I'm in Canada
John the tile will be left off after the membrane is installed...they aren't req'd.
Ron |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 2:48 pm: | |
David-
That makes a difference! Most of those "membranes" (like
"Torch-Flex"), aren't designed to be used under tile or cement,
as far as I've read.. But hell, there's something new everyday...
http://www.roofingcontractor.com/CDA/ArticleInformation/features/BNP__Features__Item/0,324 1,121647,00.html |
Peter E (Sdibaja)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 4:10 pm: | |
Ron: we are 98% there!!
This will be a walking deck/patio... I will replace the tile once I have a good water tight membrane in place. I do not care much if it cracks, it is an exterior walking surface and cracks just give it a "rustic" look.
This is not a new problem, It has been solved, I am just having a hard time finding the product.
Tile showers are not new, they use a membrane system, I just need to find what that product is and a source!
Thanks all... Peter |
niles steckbauer (Niles500)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 4:26 pm: | |
Peter -
http://frs.flatroofsolutions.com |
niles steckbauer (Niles500)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 5:50 pm: | |
Let me add a few suggestions -
First of all if you print out the above description - you can go to your local building or roofing supply house and find an identical material localy, but they may not give you contractor prices.
You do not want to lay tile directly on this surface - walking on the tile will deteriorate the surface of the membrane and drastically shorten its life - the best application I have used for your roof slope is a 1 to 2 inch layer of pea gravel screeded to a level surface (does require some type of containment at scuppers so as not to wash out) - the pea gravel will act as an addtional UV protection, provide for better drainage, provide for proper seating and support for tiles (keep them from cracking), act as grout if gently seated in gravel by maintaining horizontal stability, and provide dimensional stability for the uneven areas of the concrete surface.
You will need to cut strips of the membrane for the valleys of your scuppers and go back at least a foot from the parapet wall - install them first and then bond them to the roof membrane when it is overlayed - if your parapets are not waterproofed or deteriorating you can roll the membrane up and over it.
Hope this helps -
Niles |
Brian Brown (Fishbowlbrian)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 6:44 pm: | |
I'm with Niles. EPDM is definitely the way to go.
Here's another link... L.A. area, even: http://www.compotite.com/tile_roof_decks.htm
Let us know how it turns out!
FBB |
Stephen Fessenden (Sffess)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 11, 2005 - 4:41 pm: | |
Before you tear up the roof, be sure it is not leaking at the edges, the flashings and running to where it appears to be leaking from. I would expect that tar base covered with mortar and tile may still be water tight but water comes in at at joints in the patio roof and runs along cracks in the concrete under the tar base. Water could also run over the edge of an overhanging roof and then back through cracks and along the surface to apparentlly leak from other spots. A drip edge would fix this. What do the Mexicans recommend? They should be experts in this type of construction. |