Internal brick work growing white fur - WHY?

[suggett1976]

Ok i have just carried out a small barn conversion into a hobby room.
The origonal dwarf brick wall has now started growing white fur on the inside.

It only seems two be in two places and is below the damp cource.

All the brick was treated with a concrete/brick hardener from wickes.

I have enclosed some before and after photos and some of the white fur.

Will it stop, and why is it doing it?

 

[suggett1976]

how do i upload my pictures?

There in my profile some where!!!

 

[suggett1976]

[/img]

[img]http://i51.photobucket.com/albums/f368/suggett1976/hobby room/pic11.jpg[/img]

[img]http://i51.photobucket.com/albums/f368/suggett1976/hobby room/pic13.jpg[/img]

 

[XrayDave]

Not an expert but is it salt beeing leeched out of the sand in the mortar mix as moisture rises up through the brickwork?

Should you have used washed sand?

Dave

 

[Chukka63]

what height is the DPC cos that looks like it maybe in the course the salting stops.
You can get chemicals to stop it.washing regularly with water also cures it( no good in your case as its internal)It will stop itself once the bricks dry out but if the DPC is above the floor level it wont dry out completely 100% of the time so will come and go.if the DPC is that high then you have constant damp in those bricks and maybe further problems.

 

[Richard C]

It looks very nice but has it been subject to Building Regulation & inspection? Why is the DPC so high up the wall, was it originally outside? What sort of floor is under there? It should have been laid at a height to allow the Damp Membrane (assuming you have one) to be either coincidental or above the wall DPC. The brick courses below the DPC are always likely to suffer damp which will leach into the floor & won’t do that nice looking wood floor any good at all.

 

[jm2000]

Hi, yes its under your dpm (damp proof membrane). i am a little concerned about that as dpm is usually floor level.

Yes it looks like a bad case of salts seeping from the bricks and mortar. No need to wash, just rub with a hard brush.

You may find though that as time goes one that the 2 course of brick become damp and eventually stain the floor.....good luck....

 

[lostinfens]

Looking at your outside picture, it appears that the internal floor level is lower than outside. Also your brickwork internally is pointed rather than jointed where the salts stop. This would strongly suggest that the dpc is too high internally, the question is what idiot did this?

 

[alittlerespect]

Besides the salts problem you have a serious design flaw in relation to the dpc level of the brickwork and floor - as already mentioned, but things could get a lot worse in the near future as ground water may penetrate the whole floor slab underneath the flooring and give you all sorts of problems before you realise that you have a problem.

I would recommend that you go back to your Architect/Designer and sort out a way to resolve these problems before you have a real headache on your hands.

Otherwise it looks a really nice building!

Regards

 

[Chukka63]

simplest and cheapest option is to dig out around the building to 150mm below DPC.should be a metre wide.

 

[Richard C]

The OP seems to have rather lost interest in our efforts to help since Chukka first lit the fuse, two posts in 15 minutes & then nothing for 3 days; either gone on holiday (& who could blame ), got very worried, very embarrassed or possibly all three, whatever.

But if you’re still reading this, it would be nice to have some sort of acknowledgement/feedback of the effort various posters have made to help even if just to say don’t bother anymore.

 

[hotrod]

The OP seems to have rather lost interest in our efforts to help since Chukka first lit the fuse, two posts in 15 minutes & then nothing for 3 days; either gone on holiday (& who could blame ), got very worried, very embarrassed or possibly all three, whatever.

He's probably embarrassed Rich. He's only gone and put that DPC at the same level as his external leaf DPC. Ordinarily it wouldn't be a problem but because there's no height difference between Ext GL and FFL that's where the problem lies. He needed to make an adjustment to his internal wall DPC height to account for this. Would have been better to have raised his FFL accordingly but hey ho, easy mistake to make for those not keeping their eye on the ball.

On the plus side, always nice to see a bit of english garden wall bond

 

[Richard C]

On the plus side, always nice to see a bit of english garden wall bond

Such a shame to see what otherwise looks to be a fairly expensive & beautifully finished project tarnished by what appears to be a huge cock up by someone!

 

[lostinfens]

(On the plus side, always nice to see a bit of english garden wall bond [/quote])

Looks like bog standard English bond to me
Even with a drainage break around the wall (which could resolve the problem), there will still be possible bridging within the cavity & the sub dpc brickwork may still absorb damp from below. Only option is either injected dpc or physically cutting out & placing new dpc below damp brickwork- a slow & very tedious job. This latter option would enable you to clear the cavity as well though- good luck.

 

[Nige F]

You`re assuming the cavity is blocked... we don`t block cavities in Sussex