Shed floor

[micko]

Hi guys

My old timber frame garage needs a new floor.The frame and colourbond roof are in great condition but the old floor was eaten by termites as some clever person layed it on the soil.
Having removed the old floor and rid of termites I now need to lay a new floor.
As the outside frame is resting on bricks 6 inches below ground level,I'm not sure what to do.
Can you concrete when the frame is already there?
Should I use a yellow tongue floor on supports?
Maybe raise the shed (doubtfull)
Any suggestions

many thanks
Micko

[Daniel]

Your best bet is to use concrete in the shed floor, probably around $30 dollars a M2 to have it layed or about $120 M3 to buy yourself.

If you go down the timber road then you will need subfloor vetilation otherwise the flooring will eventually rot out.


Daniel

[Zed]

HI,

I'd go the concrete path too. If you've got the time and money you may want to consider a new shed altogether.

[IanA]

Micko,

You mention that the outside frame is on bricks below ground level. What is the condition of this frame?

If it looks pretty dodgey you would be unwise to concrete right up to it, certainly do not encase any of the timber framing in concrete.

If it's in good nick it may be worth jacking up the whole shed and then laying a new concrete floor underneath. The bottom plates (assuming they exist) could then be secured to the floor after a week or so, when the concrete has gained enough strength.

If the bottom plate and the bottom section of the studs is badly rotted or eaten I think Zed may have the answer. A new shed could be cheaper than you think.

[micko]

Thanks for the replies guys.
The Hardwood frame is still in good condition.I too think it would be best to raise and concrete then lower but i'm not sure how to do it.It's about the size of a garage.
The other way i thought of is to concrete inside the shed up to the bottom of the outside frame encasing the bricks it's sitting on now.The whole thing is sitting on about 8 brickstacks at varios points around the shed.
Do you think it matters that it's abit below ground level.
Although the shed is level ,the ground it's supported on has about a 10 inch fall lengthways.
Any more thoughts
thanks
Micko

[DarrylF]

The main thing to worry about it seems to me is keeping the timber dry - whether or not it's below ground level doesn't matter as much as being clear of concrete & earth and staying dry. Good drainage around the outside, oversized and designed to deal with leaves & soil etc.

Obviously the reason for wanting it above ground level is because it's easy over time for most types of drainage to become blocked or overwhelmed in heavy rain etc.

The best approach might be to build a setback (pathway?), below the new slab level and right around the shed. Either concrete or gravel with appropriate drainage, then a small retaining wall.

[IanA]

I like the way Darryl is thinking. Drainage can be critical when you have anything below ground level.

Two things termites absolutely love is darkness and moisture.
In any case having water run into your shed is guaranteed to wreck that lovely expensive cabinet timber you have so carefully stacked in the corner!!

If you have the space to create a path with incorporated drainage around the outside, then set the top of the path down below the edge of the floor slab. This will create a decent physical break below the bottom plate which will make future inspections for termites much easier.

Dig out the area around the shed, box up for the concrete floor outside the timber frame, and when you pour the concrete for the floor take time to compact it well under the bottom plate.

Encasing the existing brick stacks is not ideal cos it could give a hidden access point for termites in the future.
Maybe put temporary boxing around them so they can be removed later and replaced with concrete.

[micko]

thanks guys
I don't see how I can concrete it up without enclosing the brick stacks.After all they are holding up the outside frame.

micko

[DarrylF]

Since you say the frame is in great condition, then I guess the termites haven't got to it so far. I'm no expert on termites but I guess if they haven't attacked the frame already, and you have it all professionally sprayed when you're done, then you should be OK.

The only way I can think of not enclosing the brick stacks is to replace them. Pouring new concrete footings next to the current brick ones then removing the bricks might be one way to do it I guess. Personally I'd only be thinking of doing that if the bricks are a problem - unstable, contain voids etc.

Any chance of getting termimesh or metal capping in between the top of the bricks and the frame?

[IanA]

Darryl's idea of a physical barrier between the bricks and the frame is a good one.

Don't put too much faith in the chemical barrier. The manufacturers of the stuff will only guarantee it for about 5 or 6 years. Not much in the life of a shed eh?

Dieldrin and Heptachlor might have been long term nasties, but they also provided a long term barrier. From the poit of view of termite control it's a pity they have been banned.

Steel framing is the long term answer.

What a terrible thing to say on a woodwork site!! Wash my mouth out.

[Oldblock]

Lots of good advice so far. Concrete best way to go.
The answer depends on your capabilities and budget.
Golden rules:
Floor at least 100 above highest ground
Dampproof layer under concrete spay under concrete to protect DP membrane and perimeter spray after all earthworks are complete around outside.
With floor above ground any termite attack later on will be visible
Mechanical termite barrier not needed if points of entry are visible for inspection
Let concrete reach outer face of walls thus supporting walls = brick 'stacks' no longer prime means of support.

Nothing to it! Whats keeping you?

[Oldblock]

Should have checked my posting before submitting.
For spray under concrete read spray pad before laying DP membrane.