DPC weakness dont know what to do next

[moconnell]

Hi All,


Please help me with this bricklaying / finishing issue

I'd just finished my dwarf / retaining walls (sloped garden shed base) on which to put my wall/sill plate on for the rest of the shed.

I had a last row of blue bricks that I had put a DPC beneath (since the highest part of the surrounding land just got to 150mm clearing, but on other side is a 700mm). When I was laying it my inner voice was just telling me ' how can this be right it's never going go bond well enough'... but with speedy laying it appeared to set OK. However I decided to only DPC my outer cavity wall and skip the inner one.

Then I read a lot of conflicting advice we need to use chemical anchors in really and then that no wall straps are needed...so I decided to try both.

I put the a few anchors in but when I drilled the holes I wanted to do a test fit so put it on the couldn't get it off again so tried pulling it up and (obviously in retrospect) it pulled almost a whole row of bricks!

So I don't know what to do next I am not sure on the thinking/rationale for DPC layers now...I mean it seems to simply weaken the brick layer sooo much (I'm pretty sure the mortering was good) that I don't understand how the whole industry can justify it?

What should I do next?
My Options as i see it:-
- leave DPC in place, remortar on top to get lay bricks in same way.Then don't try chem anchors and use the umpteen wall straps I have.

OR

- remove DPM.. relay row with just mortar..put on DPM on top of lat brick instead and lay the sill/wall plate and then wall straps? (Although I have 3 more wall like this but not been broken by me yet).

I'm really pi**ed right now as I only had today left before I go away and I'm not going to get this wall plate fitted now

 

[Ivor Windybottom]

All buildings that have a DPC are pretty much held in place by friction and weight. Normally there is a whole wall on top of it, not just one course as you have.

How is a timber-framed house normally built? I don't know myself, but I'd imagine it's not normally done like this.

 

[moconnell]

Yes OK but this is half timber on to of brick on a slope...so none of the terms I google ever come up with anything so I've freestyled it.
Which of the options would you suggest?

I find the dpc is fairly slippy we've got a lot of buildings resting on this in the uk to I guess it must be ok but makes me nervous personally...

 

[^woody^]

I don't know exactly what your doing, but generally for timber frames there is a DPC beneath the sole plate, and/or a cavity tray to prevent moisture in the cavity from running down the frame and across at the sole plate. The frame does not need fixing down, but normal corrosion resistant screws and plugs or frame anchors (Hammerfix) will do. Certainly not chemical fixings.

A DPC on the outer leaf only is doing nothing. But again generally, a building is retained on the DPC by friction, and slight expansion sliding is normal and advantageous. However you would not normally build a freestanding wall on a DPC.

BTW, you should fill the frogs in those bricks before laying a DPC or sole plate on them.

 

[Ivor Windybottom]

Yes OK but this is half timber on to of brick on a slope...so none of the terms I google ever come up with anything so I've freestyled it.

I don't know what you've been searching for, but there must be lots of diagrams of how any sort of building is constructed. I'm a lowly enthusiastic amateur but can immediately see it's wrong. Perhaps make a cuppa and get finding out.

DPCs are slippery if there's just one brick on top. But I can go outside and push as hard as I like against my house and I'm absolutely certain it won't move!

 

[moconnell]

I'm going to just remortar and hope that given the straps and the eventual weight of the timber superstructure give me the stability I'm hoping for..

 

[noseall]

I'm going to just remortar and hope that given the straps and the eventual weight of the timber superstructure give me the stability I'm hoping for..

Get some blue solids (no perf's), if you are to fix to them.

 

[^woody^]

And a damn good drill and bit.

 

[Ivor Windybottom]

They're going to shake and loosen or spin off, however good the drill and bit. You're still only screwing into one brick, you might as well not bother and just rest the frame on top without fixings, rather than screwing it to a 2kg brick.

There must be a proper way of doing this, if this was my project I'd be finding out, but this method seems silly.

If drilling the brick really is the best way then perhaps drill and plug it before bricklaying?

 

[moconnell]

Have straps ready have a 2 courses to screw in to on the highest and like ten on the other...

Gave up and having it waiting to deal with when I get back from holiday