DIY Home Improvement Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Good afternoon,

I have read every resource I can find regarding proper techniques for preparing and installing t&g doug fir porch decking. One question that has not really been addressed is, should I gap the decking when I install it?

A bit of background...

We live in Seattle, WA (wet), and we have a large covered front porch. The porch is north-facing, so it gets only indirect sun, and that only for about 3 days during July (ok, just kidding about that, sort of.) But we CAN expect the decking to get wet.

The porch is over a basement room (concrete floor and walls) that has a closed door separating it from the rest of the basement. I intend to keep the door shut and ventilate this room to the outdoors, to keep the humidity equal above and below the decking. We'll use it to store bicycles, turnips, children, and other cold-tolerant stuff.

I plan to do the following:

- Pre-treat the boards with borate or other suitable preservative.

- Apply finish (paint or varnish) prior to installation.

- Use Vycor deck protector or equivalent on the framing members.

- Install the decking with appropriate slope for drainage.

That just leaves the question of gapping. I don't think I have ever seen t&g installed with a gap. Should I gap it to allow for possible expansion? If so, how much gap should I give it?

Thanks,
- Mark
 

·
JUSTA MEMBER
Joined
·
17,356 Posts
No gap.

If you do your Children, Turnips and other things are going to get wet, and spoil.

Spoiled kids are the worst.
They grow up to become the President, and think that they are better than everybody.

Seriously T&G is designed to be tight., so no gaps needed.


If you want to allow air in you need to raise it up a little on shims or spacers to allow air flow.


ED
 

·
Usually Confused
Joined
·
7,749 Posts
I agree that T&G is intended to be installed tight, but I am having trouble envisioning your construction: you have a sub-grade room that is part of the house structure and that has a wooden porch for a roof? It seems all rather 'un-sealed'. What is there now (before the T&G)? Maybe I'm just not getting construction practices in other parts of the world.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #4 ·
Yes, it is a basement room with a wood porch floor for a roof. It is a very old house (1895-ish), I have no idea what the original configuration was. The old decking was a narrower t&g, which is still in place (at least in some places.) It is undoubtedly too rotten to salvage. At some point it was covered with plywood and then an ugly gray vinyl membrane. That makes the room underneath nice and watertight, but the porch is about as attractive as a torchdown roof.

- Mark
 

·
Super Moderator
Joined
·
12,524 Posts

·
Super Moderator
Joined
·
12,524 Posts
We are planning to use a clear finish (aka "varnish.") Any particular recommendations?
That's a tough one (especially for Seattle).
If it was railings or doors Id use a Marine Spar Varnish but I don't know if that would be a good choice for a walkable surface.

You may want to start a thread in the painting section of this site with that specific question.
 

·
General contractor/carpen
Joined
·
15,532 Posts
If it's T&G it's more than likely kiln dried, so movement shouldn't be an issue. No gap.

_________
 
1 - 9 of 9 Posts
Top