Damp course question

Rich_D · 13 Apr 2022

I have cut out the bricks before having a UPVC personal door in stalled in my garage. The old felt damp course ripped when the course of bricks were removed. I have a roll of modern plastic damp course Should this go straight on top of the bricks or shall I lay a mortar course under the new damp course? Thanks for any advice.

mikej460 · 13 Apr 2022

Straight onto the bricks (when laying a DPC bricklayers may put a thin skim of mortar onto the bricks just to stick the DPC down then a line of mortar on top). Normally you would cut a100mm slot into the mortar each side of the doorway to ensure the correct overlap but I'm wondering whether you need a dpc with a upvc door anyway?

Bingy man · 13 Apr 2022

mikej460 said:
Straight onto the bricks (when laying a DPC bricklayers may put a thin skim of mortar onto the bricks just to stick the DPC down then a line of mortar on top). Normally you would cut a100mm slot into the mortar each side of the doorway to ensure the correct overlap but I'm wondering whether you need a dpc with a upvc door anyway?

Your reply makes complete sense ( 100mm into mortar ) if nothing else it will prevent damp travelling laterally into the brickwork should that area be subject to flooding or even excess rain . I see your point as regards a upvc door/ frame but as the frame is not yet fitted it can’t do any harm to replace it .

Rich_D · 13 Apr 2022

I think the door sill/frame will sit straight on top of the damp course or would a course of bricks between the damp course and door be a better option. The door company need dimensions of the opening thanks

Bingy man · 14 Apr 2022

Rich_D said:
I think the door sill/frame will sit straight on top of the damp course or would a course of bricks between the damp course and door be a better option. The door company need dimensions of the opening thanks

If I was installing the door/frame I’d simply lay thin bed of mortar approx 1/2” to 3/4 inches on top of your doc -measure then from top of mortar bed to the top of your opening. If the manufacturer makes a mistake with the frame size or your measurements

you then have a get out of jail card of 1/2 “ to 3/4 “ which can easily be removed and any gaps dealt with using appropriate frame sealant.. ( just my opinion)