DPC on single block garage.

[skinters]

I'm well into a block shed project,,and i have the corners in so far.

My mate is laying the blocks for me ,and everything looks good,but i think ive made a mistake with the damp proof course.

We have layed it on the footings,but i have stupidly realized that it might be useless seeing as the the slabs ill be laying will be obviously higher than the DPC.


I know i can fall the slabs away from the building,but i dont know if it will be enough.

Would putting in a drip a foot up from the bottom also help ?.

 

[freddiemercurystwin]

Any moisture will leach through any blockwork below ground. If you can you should link your dpm under the slab with the dpc in the wall which should obviously be above ground level. Any single skin garage will potentially be prone to a bit of damp btw.

If it were mine I'd push the walls over and knock the mortar off the blocks before it goes off.

 

[cotswoldbuilders]

As previously said, you will get moisture through a single skin wall, if thats the only corner you have set up, step the dpc up on the rest of the walls.
When you put the membrane in prior to concreting, make sure it goes up the wall, then trim of after.

 

[tim00]

1. If you have racked up four corners, then either pull them down to one block height, or as suggested, leave the corners alone, and lay the remainder of the DPC at the one block high height. However, water will penetrate and by-pass the DPC now in position ( see 3 below ).
2. Perhaps you should come back here for more general forum advice ref. your project. I say this because:
a. you have not completed your groundwork inside the walls.
b. the blocks are not positioned for efficient laying.
c. the site is disorganised.
3. Typically, for a garage slab, you would prep and pour one single slab, with the surface 150mm above ground level. What you are doing will possibly give you difficulties down the road.
Given that you do intend a full slab?

 

[skinters]

a. you have not completed your groundwork inside the walls.

I thought it was normal practice to complete the floor last with strip foundations ?.

Given that you do intend a full slab?

Yes i will be doing a full slab.[/quote]

 

[cotswoldbuilders]

You normally bring all block/brickwork up to dpc level, then hardcore, membrane and visqueen prior to concrete base.
Once that stage is done, dpc then walls.