Mortar over DPC, spalling off
Mortar over DPC, spalling off
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Discussion

ALawson

Original Poster:

8,024 posts

275 months

Sunday 3rd April 2011
quotequote all
We recently moved house and I have noticed that mortar that was covering up the DPC on the outside face of the brickwork is breaking away/spalling.

To explain it looks like the DPC has been "pointed up" around the perimeter of the house.

I would have thought that you wouldn't want any thing to be able to bridge the DPC, i.e. form a moisture carrier between the mortar below and above the DPC.

The house is about 15 years old and other down the same Close have the same detail on the DPC.

Is it something to worry about? Does it need re-instating? Should I be worried about the cause, from memory it occured around the cold weather earlier in the year.

Any suggestions/advice appreciated.

Regards

Alex

Sam_68

9,939 posts

269 months

Sunday 3rd April 2011
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Recent BRE research suggests that DPC's in the external leaf of cavit walls aren't as critical as most people would think - even if rising moisture bridges the DPC, you've got a cavity to prevent it getting anywhere where it can do serious damage, and of course the external leaf of the wall is frequently exposed to driven rain itself.

Your problme is fairly common and is caused by the DPC itself; water hitting the exposed outer leaf is collects on the impermeable DPC where it will then freeze and acclerate frost damage to the mortar.

By all means get it re-pointed if its bad, but I wouldn't worry about it too much.

Spudler

3,985 posts

220 months

Sunday 3rd April 2011
quotequote all
Nothing to worry about at all, purely cosmetic.

ALawson

Original Poster:

8,024 posts

275 months

Sunday 3rd April 2011
quotequote all
Sweet as a nut.

I wasn't to worried...Honest.

Skyedriver

22,396 posts

306 months

Monday 4th April 2011
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Similar situation, DPC works superbly its the rubbish London bricks below that are disintegrating.