DIY shed - damp proofing base

[bens]

Hello,

I'm looking for advice please on damp proofing my new (build from scratch) shed base.

The shed is a lean-to building, attached to the side of the side.

3x2 pressure treated frame for base and walls.

Below the timber floor frame was an existing base from a path covering half the area so in my wisdom I decided to try to use concrete slabs (concreted in place) on the other half and then lay the frame on top - following a brick line in the house to keep it level longways. I have now filled the gaps beneath the frame with concrete (not shown in pic) - it now feels very solid and the bounce has gone. I also didn't want to concrete this other half as it was banked up and there are now pipes just under the height I've dug to.

I did unfortunately forget about damp proofing and I'd rather not life the timber frame if possible as concreted in and bolted to the wall.

Would it be suitable to use a DPM (I've already bought a load from Screwfix) on top of the frame? (as well as wrapping the walls in it).

Pics attached.

I am a complete novice at this! (as you'll probably tell from the pics).

Thanks, Ben

Untitled

• bens
• 12 Sep 2014
• 1

Untitled

• bens
• 12 Sep 2014
• 1

 

[EddieM]

No, what you suggested isn't going to work, easiest solution is probably to put DPC tape (you could get away with butchering the DPM i guess) underneath the frame where it meets the concrete, and even better solution would have been to create a solid concrete slab with a DPM incorportated.

 

[bens]

Thank you very much for the reply.

Am I right in thinking, if I apply the DPM over the top, will this still protect the rest of the building but leave the base vulnerable to damp, hence causing it to rot quicker?

The base is pretty firmly in place now so weighing up the pros and cons of not doing it.

Thanks

Ben

 

[EddieM]

Is the timber pressure treated?

 

[bens]

Hello,

Yes, pressure treated 3x2.

Ben

 

[EddieM]

Well, as you have the DPM I'd use it as you described, but yes the frame will eventually rot, but not for quite some time.

 

[bens]

Thank you both, appreciate your input