Replies

1. 
   Dinosaur | Jul 09, 2005 05:41am | #1

   I'm not familiar with the Duradeck product you mention. If you could describe it a bit that'd help.

   But generally, the issues with decking over a roof are (1) assuring drainage; (2) keeping penetrations to a minimum; and (3) distributing the load properly, since most roofs are not designed to function as floors.

   Your slope at 2" in 12' should be sufficient as it gives you a bit over an eighth per foot. If the roof construction makes it possible to do so, try to lay your sleepers parallel to the slope so you don't have to drill/cut weep holes in them. Locate them directly over the rafters or trusses; that way the load from the deck won't be transferred to the roof sheathing but directly into the structural framing.

   Your sleepers need to run just a bit past the eaves edge of the roof so you can mount the rim joist/sub-fascia in a manner to leave the eaves free for drainage. You can hide this gap by using a finish fascia board that is deep enough to overlap the eave.

   If the product you mentioned is not a self-sealing roofing membrane, consider adding one so that the nail or /screw holes used to hold the sleepers in place don't leak.

   Since the sleepers will be lying in contact with a roof and will certainly have water weep under them through capillary action, they need to be rot resistant. I'd recommend you use cedar 2x for them. In fact, because of the lower weight of cedar, it's a good material to use for the entire deck. You'll need to use stainless steel screws or nails with this to avoid staining.

    

   Dinosaur

   A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...

   

   But it is not this day.

1. 
   netorius | Jul 09, 2005 07:38am | #2

   thanks for your quick reply. very informative and detailed.

   Duradeck is a kind of like vinyl flooring for decks. It's heavy duty and is put down with contact cement or something like it anyways..

   The method currently being used is exactly as described by you but no nailing goes through the duradeck.. the sleepers are held in place with a 2" wide length of rolled window caulking.. i'm not sure where,why,how but it says on the box window caulking or sealent i believe, it comes in big rolls and 2" wide. and is as you can imagine sticky both sides.

   I'm looking for alternatives that others may be using or suggestions, as this method (as with any) has drawbacks.. Railings for example.. with not wanting to penetrate the duradeck fastening 6x6 posts is a bit of a pain.  we either have to put blocking in the roof, and fasten the steel plate that holds the post on with bolts and silicone. or the steel plate is mounted on top of the decking boards with blocking under neath. The first is prone to leaking,, the second isn't as secure.

   for mounting the posts we use a 7"x7" 1/4 thick steel plate that has a 2" x 10" steel pin welded to it, the 6x6 post is drilled and driven onto pin with a sledge hammer.. then the post is leveled and bolted or lagged to deck/roof.

   what other products are people using for the roofing, rubber, Brai, etc.. 

   what about sealing?? I would like to be able to do the roof sheeting,, mount posts and seal up and around the posts.

    

   thanks