Green Mould - 4 months after damp course treatment!

[kerrys2002]

In response to your comments:

The injection was either done from inside - which means 200mm of wall above the injection is exposed to lateral penetration. - The injection was done internally, I'm not sure what difference (if any) this makes.

That will take several months though so in the meantime an anti mould paint will help to keep it back. - Would I use the anti mould paint internally, externally or both? Is there a paint you would recommend?

If I were you I'd concentrate on getting the external levels sorted. - I will not have any money (having just bought the house 5 months ago) to fix the external levels until Spring (at the earliest). Will that be a major issue? Can I use the anti mould paint in the interim?

What repairs are you thinking they will (can) do? The mould is not dampness, it's condensation. - I appreciate that there might be nothing to fix but do you think their opinion on the wood over MDF and the possible puncture of the tanking will affect the 10 year tanking guarantee in any way?

I will report back what the surveyor makes of the situation after viewing it tomorrow. I will also provide pictures of the external areas for your review.

Again, a huge thanks to you both for your help and advice!

 

[jeds]

MDF or wood skirting affects nothing either way so isn't a factor. On the screws through the tanking; It depends where (if) any dampness appears. If you get dampness around the screw holes you're going to have to deal with it yourself. On the other hand if you get dampness appearing somewhere away from the screw holes - but not around the screw holes themselves - then that would suggest a failure of the tanking and I'd expect them to deal with it. Ask them to test the skirting near the corners and also away from the corners and show you how damp/dry they are. Make a note of the percentage moisture content that shows?

As for the ground levels. Could you not do a bit of digging yourself and then have it made good in Spring. A narrow trench along the wall backfilled with stone would make a big difference to the amount of water getting into the wall.

 

[Johnmelad]

Take the skirting boards off and see what their backs are like.

 

[kerrys2002]

Hi all,

I attach some pictures of the internal skirting and wall which the company claim the screw could have punctured the tanking and I include pictures of the external walls.

I have also re-labelled the sketch plan marking out the walls as 1, 2 and 3 and each picture should correspond with that.

It also looks as if wall no. 3 was injected externally.

I look forward to your reviews and as always, thanks for your help.

 

[kerrys2002]

Damp - Internal

View media item 69360 View media item 69359 View media item 69361 View media item 69362 View media item 69363

 

[kerrys2002]

Damp - External

View media item 69364 View media item 69365 View media item 69368 View media item 69369 View media item 69370 View media item 69371 View media item 69372

 

[kerrys2002]

Sketch Plan

View media item 69373

 

[jeds]

Looks like a bit of a mess to me. It looks like they've rendered down onto the timber floor. Is that right or does the render extend below floor level? It also looks like your external air vents are completely blocked. Is that right? If so unblock them immediately. I'm struggling to work out the photo marked 'Wall no. 3'. Is that render on top of pink plaster? The dark patches on the pink plaster may be penetrating dampness but it might also be condensation forming behind the skirting. The mould growth is definitely condensation. It is very difficult to be precise without being able to fully inspect and take moisture measurements, but one thing is for sure; until you reduce external ground levels and sort out external drainage those walls are never going to dry out. The air vents are very important - did this preservation company not mention them to you? Also, did they not mention ground levels? Are they a bona fide company or a local builder?

 

[kerrys2002]

Thanks very much John. In reply to your questions:

It looks like they've rendered down onto the timber floor. Is that right or does the render extend below floor level? The flooring was laid after the work was complete. The rendering would have been done to floor level but not below.

It also looks like your external air vents are completely blocked. Is that right? You could be right. If so unblock them immediately. I will do this ASAP. At the risk of sounding totally blonde, can you recommend how I go about unblocking them?

I'm struggling to work out the photo marked 'Wall no. 3'. Is that render on top of pink plaster? The top of the picture is the paint on the wall, the bottom is where the skirting would have been.

The air vents are very important - did this preservation company not mention them to you? They mention nothing in their report about the air vents.

Also, did they not mention ground levels? They mention nothing in their report about the ground levels.

Are they a bona fide company or a local builder? They are (supposedly), a bona fide company. If you Google "damp course is Essex", they are the second company listed beginning with K.

Until you reduce external ground levels and sort out external drainage those walls are never going to dry out. In your opinion, what would be the best way to reduce the ground levels? Dig out the entire back patio? Or install french drains? My concern regarding wall 3 is that my front path is directly attached to the neighbours so I'm not sure how I would reduce the ground level without affect theirs? Should I use french drains at the front of the house?

Thank you![/b]

 

[jeds]

Unblocking the vents depends what's blocking them. It looks like mortar which might mean drilling it out or something. Difficult to say from a distance. Have a poke around with a screwdriver or something and see what happens. If it's hard mortar you might have to get a builder to look at it.

I'm very surprised a damp proofing surveyor would not mention the ground levels and blocked vents. Those two things are fundamentals. If it were me I'd ask for details of the surveyors qualifications and experience.

What you do with the patio and hard surfaces depends on the available drainage. The priority is to remove any water holding material away from the house wall and to direct water away from the house - preferably to a drain outlet. If there is a drain available and the falls work correctly then cut around the edges, reduce levels and install a drain to the outlet. Otherwise a French drain is the next best option - but the water still needs somewhere to go. Otherwise you'll just end up with a trench full of water around the house.

Really you need somebody independent to look at the whole lot for you. A local chartered building surveyor with damp treatment experience would be best. It will cost you but you can ask for advice on the work you've had done and on the best way to tackle the external levels and drainage. Phone a couple and ask for some prices.

 

[kerrys2002]

Apologies for the delayed update, PC issues!

The company sent someone Thursday afternoon to check the mould.

His view is that the mould is caused by condensation as the walls are still drying out (the work was done in July) and will continue to dry out for some time. The corner where the mould is growing is apparently on the 'coldest part of the house - the area that receives the least amount of sun'. The area was not wet or damp so he concludes that the treatment is working. He didn't take any readings or use any gadgets, this was all just by looking at it.

I mentioned my concern regarding the external levels and ventilation and the possible impact they could be having on the internal walls. He told me that whilst the external levels are high, the company performed a procedure called 'tanking' which in theory, raises the internal level by 6 inches. This is the amount they recommend you need to raise and this is a procedure which they perform in basements. He said that if I wanted to, I could fit French drains but the tanking should work so I don't have to do anything to the external levels.

He also said that I had punctured the tanking with the screw. I asked how I could puncture it when he had just explained that 'tanking' is painted onto the brickwork? He stood by is view and said that I had but that there was no damage to the treatment.

He said I could reattach the skirting, once the mould had been cleaned off. He said not to reattach with screws and to glue it. I argue this point as the holes have already been made so why can't I just screw it back on?! Any views? I mentioned the anti mould paint and he said to paint it onto the skirting once attached to prevent the mould from returning whilst the walls dry out.

He will be sending me a report in the next couple of days and I will put the information on here.

At John's suggestion, I have booked for a Chartered Surveyor to come and look at the internal walls and external levels tomorrow morning. I'd prefer an independent opinion as the company was always going to tell me that their work was done correctly!