Q-Con Water Absorption. How to correct?

[Mike45]

We took possession of the new house last December. We haven't been there since then but SIL checks on it every couple of weeks. This week she has noticed this problem.

The builder that warranties the house just wants to paint over it.

What is the correct way to correct this problem? Which process and products should be used?

Thanks

Mike

[lopburi3]

Search rising damp

https://www.google.com/search?q=rising+damp&ie=utf-8&oe=utf-8&aq=t&gws_rd=ssl

There should be a barrier in place to stop but know nothing about Q-Con but believed it did not absorb water and actually could float. Or is it something else at base?

My old house built 40 years ago of red brick had such an issue and used ceramic tile on walls with problem - but now have french drains pumped out so water level never gets high in plot so that also seems to take care of it.

[stoneyboy]

Search rising damp

https://www.google.com/search?q=rising+damp&ie=utf-8&oe=utf-8&aq=t&gws_rd=ssl

I got this.

[lopburi3]

Brits always find the comedy.

It must be a weather thing.

[gerry123]

you are screwed mate dont believe all the stories about lime and salt residue its definatly rising damp actually more like rising water you will have to excavate completly around the footings (joke i know)and try and water proof the exterior with a quality bitumen based covering

for the bits where you cannot reach you are stuffed a rebuild comes to mind with a strong damp course something unheard of in los

[eyecatcher]

……and I was going to say; yes search rising damp and you will realise very soon that its probably not.

So lets have a discussion.

I tried to establish a pattern from the photos buts its unclear so jumping to conclusions without a proper appraisal is just silly and doesn’t give the OP much confidence.

Its appears that some of the photos are inside the house and some outside.

You say the house is built from Qcon blocks. Ok first things; an aerated block such as this absorbs very little water, maybe only 1cm across a 75/100/125 block it simply has too many air cavities and that’s why heat cannot travel through it.

So lets assume the blocks are at or above ground level then is water going to rise 400mm? doubtful unless you have a flood.

There is a photo of what appears to be a plinth line, normally that would be the concrete ground beam and wall junction. If that’s the case then it appears there is exactly the same “rise” in damp though solid concrete at the aerated concrete which isn’t feasible.

One photo shows what appears to be an outside path. I am more inclined to think…..and contrary to Gerry opinion about salts, ...rising damp carries no salt, and no efflorescence generally.

I think most of these are rain splashes, heavy splashes, the same as you see around most house wall bases. The bottom of the wall is getting splashback and that rain has caused “cheaper” paint to blister.

How did water get in to blister it, well one reason could be the walls were rendered and not allowed to properly dry out before the painter came along; thus the moisture in the render was trapped.

Does your external wall staining coincide with the path around the house? Is it generally on one side of the house. For me my west side of the house gets the most rain .

You have to be a detective to solve these riddles but its not difficult.

You show one photo the corner by the door, with floor tiles (outside?) does water by any chance collect there?

Get your man to take more photos, now, while the wet season is with us. Its been a very dry wet season so there is no reason to believe the water table has significantly increase (yet)

I am interested in the photo showing the door jamb/hinge. It looks like efflorescence but it could be flaking paint or it could be both, this is probably the most important photo as its inside but difficult to draw a conclusion.

There is another factor and I am not sure how relevant this is. QCon blocks are not laid with traditional mortar, they should be laid with a special adhesive (I think siam bag no 23) and its spread only 1/8 inch thick. The render also has to be a special mix, perhaps special because it has the “stick” properties or maybe it has a sealer in it but essentially normal render mix is a no no. you need to check what they used.

Get some more photos OP so it gives a better picture; but whilst my opinion is based on your photos and my experience I am more incline at this stage to go with a combination of penetrating damp and inadequate preparation before painting.

In the first instance I would be inclined to wire brush the defective areas and monitor how the tide marks progress during this wet season. Then during November time you may have reached a conclusion. If it didn’t get worse then its seasonal. Reapply an appropriate paint; even silicone wash some of the walls if you are worried.

As for the builder, painting over anything now is a ridiculous suggestion, if you want to make use of his time then get him to wire brush/scrape off all the blistered paint and get him to agree to return in 3 months to check the state of play.

[eyecatcher]

you are screwed mate dont believe all the stories about lime and salt residue its definatly rising damp actually more like rising water you will have to excavate completly around the footings (joke i know)and try and water proof the exterior with a quality bitumen based covering

for the bits where you cannot reach you are stuffed a rebuild comes to mind with a strong damp course something unheard of in los

Turn it into sarcasm Gerry I am a negative person too and I love being sarcastic.

And people don’t quite know if you’re being serious or not.

[fang37]

I assume that you are referring to Q-Con bricks.

Q-Con strongly recommend that you use Q-Con "cement" when doing the brickwork.

We have had no problems. To the contrary, the insulating effects are quite noticeable.

[Mike45]

……and I was going to say; yes search rising damp and you will realise very soon that its probably not.

So lets have a discussion.

I tried to establish a pattern from the photos buts its unclear so jumping to conclusions without a proper appraisal is just silly and doesn’t give the OP much confidence.

Its appears that some of the photos are inside the house and some outside.

You say the house is built from Qcon blocks. Ok first things; an aerated block such as this absorbs very little water, maybe only 1cm across a 75/100/125 block it simply has too many air cavities and that’s why heat cannot travel through it.

So lets assume the blocks are at or above ground level then is water going to rise 400mm? doubtful unless you have a flood.

There is a photo of what appears to be a plinth line, normally that would be the concrete ground beam and wall junction. If that’s the case then it appears there is exactly the same “rise” in damp though solid concrete at the aerated concrete which isn’t feasible.

One photo shows what appears to be an outside path. I am more inclined to think…..and contrary to Gerry opinion about salts, ...rising damp carries no salt, and no efflorescence generally.

I think most of these are rain splashes, heavy splashes, the same as you see around most house wall bases. The bottom of the wall is getting splashback and that rain has caused “cheaper” paint to blister.

How did water get in to blister it, well one reason could be the walls were rendered and not allowed to properly dry out before the painter came along; thus the moisture in the render was trapped.

Does your external wall staining coincide with the path around the house? Is it generally on one side of the house. For me my west side of the house gets the most rain .

You have to be a detective to solve these riddles but its not difficult.

You show one photo the corner by the door, with floor tiles (outside?) does water by any chance collect there?

Get your man to take more photos, now, while the wet season is with us. Its been a very dry wet season so there is no reason to believe the water table has significantly increase (yet)

I am interested in the photo showing the door jamb/hinge. It looks like efflorescence but it could be flaking paint or it could be both, this is probably the most important photo as its inside but difficult to draw a conclusion.

There is another factor and I am not sure how relevant this is. QCon blocks are not laid with traditional mortar, they should be laid with a special adhesive (I think siam bag no 23) and its spread only 1/8 inch thick. The render also has to be a special mix, perhaps special because it has the “stick” properties or maybe it has a sealer in it but essentially normal render mix is a no no. you need to check what they used.

Get some more photos OP so it gives a better picture; but whilst my opinion is based on your photos and my experience I am more incline at this stage to go with a combination of penetrating damp and inadequate preparation before painting.

In the first instance I would be inclined to wire brush the defective areas and monitor how the tide marks progress during this wet season. Then during November time you may have reached a conclusion. If it didn’t get worse then its seasonal. Reapply an appropriate paint; even silicone wash some of the walls if you are worried.

As for the builder, painting over anything now is a ridiculous suggestion, if you want to make use of his time then get him to wire brush/scrape off all the blistered paint and get him to agree to return in 3 months to check the state of play.

Eyecatcher

I'll try to clarify what your looking at.

This first photo is of an outside walkway. Two stories above this area there is a gutter.

The second photo shows where the walkway is located on the house. It's on the left side of the house. It's under the window between the tarps.

The tarps were placed recently by my brother in law because it appears that wind driven rain was blowing through the large front double doors. The doors have no weatherstripping. All I know for sure is my sister in law visited the house and there was a large puddle on the floor in front of the front door. I asked them to use a tarp to shield the door. They went overboard.

The third photo is up the steps on the left of the house. It's the first French door again under the additions roof. It doesn't rain here but water does collect here because the slab isn't pitched correctly.

The next two inside photos are of this same corner but inside the house.

The next photo is of the back of the house. You can see another set of French doors fully covered by the roof but again water collects here against the doors.

The next photo is a closer view of that rear corner door.

The next photo is of the front of the house. You can see a small partial roof with a gutter under the car sala.

The next photo is showing the front right corner of the house that is under that partial roof with the gutter.

I believe most of the damage was done by standing water collecting against the house. I also remember they had to repaint these areas before we took the house.

[bankruatsteve]

Nobody suspects the paint? I'm guessing it got the normal crap paint job and that's a result. Scrape/sand, re-prime, re-paint with undiluted premium paint.

[kamalabob2]

I recently sourced some house building materials for my wife who built a modest one bedroom, one bathroom two car garage on her village land. I had Mr. Pitichai of Q-Con provide technical advise to the relatives who had very little previous building experience with autoclaved areated AAC light weight wall blocks. The Buriram Builders Merchants who gave my wife the lowest price on 7.5 thick by 20 cm high by 60 cm long Q Con blocks also arranged technical advise from Q-Con staff. I believe the OP should contact the builders merchant store who provided the Q Con wall blocks and have a Q Con technical advisor go in person to his house in Thailand. The staff I spoke with in April 2015 of Q Con were polite and professional. The OP getting the Thai speaking technical advisor to give real solutions to him and the Thai House Building Contractor for the problem will be of genuine help.

I believe that Eyecatcher has brought up a valid observation: "I think most of these are rain splashes, heavy splashes, the same as you see around most house wall bases. The bottom of the wall is getting splashback and that rain has caused “cheaper” paint to blister.

How did water get in to blister it, well one reason could be the walls were rendered and not allowed to properly dry out before the painter came along; thus the moisture in the render was trapped."

[lopburi3]

The damage in confined to the lower wall area so does not appear to be related to quality of paint (you can see the water trying to get through the paint to the air so it can dry). . New paint will suffer the same - as he said it already had to be repainted when he bought it. Also it is not even in most photos so not external standing water mark (which would be as straight as a level).

[Mike45]

I recently sourced some house building materials for my wife who built a modest one bedroom, one bathroom two car garage on her village land. I had Mr. Pitichai of Q-Con provide technical advise to the relatives who had very little previous building experience with autoclaved areated AAC light weight wall blocks. The Buriram Builders Merchants who gave my wife the lowest price on 7.5 thick by 20 cm high by 60 cm long Q Con blocks also arranged technical advise from Q-Con staff. I believe the OP should contact the builders merchant store who provided the Q Con wall blocks and have a Q Con technical advisor go in person to his house in Thailand. The staff I spoke with in April 2015 of Q Con were polite and professional. The OP getting the Thai speaking technical advisor to give real solutions to him and the Thai House Building Contractor for the problem will be of genuine help.

I believe that Eyecatcher has brought up a valid observation: "I think most of these are rain splashes, heavy splashes, the same as you see around most house wall bases. The bottom of the wall is getting splashback and that rain has caused “cheaper” paint to blister.

How did water get in to blister it, well one reason could be the walls were rendered and not allowed to properly dry out before the painter came along; thus the moisture in the render was trapped."

Kamalabob2

Getting advice directly from Q-Con is a good idea. I found their Facebook page and it says that they are " very responsive to messages"

I sent them a message in English and Thai requesting that a technical advisor come to the house and advise my builder. Messenger for Facebook even gave me the opportunity to upload the photos.

Thanks for the suggestion!

[Mike45]

I recently sourced some house building materials for my wife who built a modest one bedroom, one bathroom two car garage on her village land. I had Mr. Pitichai of Q-Con provide technical advise to the relatives who had very little previous building experience with autoclaved areated AAC light weight wall blocks. The Buriram Builders Merchants who gave my wife the lowest price on 7.5 thick by 20 cm high by 60 cm long Q Con blocks also arranged technical advise from Q-Con staff. I believe the OP should contact the builders merchant store who provided the Q Con wall blocks and have a Q Con technical advisor go in person to his house in Thailand. The staff I spoke with in April 2015 of Q Con were polite and professional. The OP getting the Thai speaking technical advisor to give real solutions to him and the Thai House Building Contractor for the problem will be of genuine help.

I believe that Eyecatcher has brought up a valid observation: "I think most of these are rain splashes, heavy splashes, the same as you see around most house wall bases. The bottom of the wall is getting splashback and that rain has caused “cheaper” paint to blister.

How did water get in to blister it, well one reason could be the walls were rendered and not allowed to properly dry out before the painter came along; thus the moisture in the render was trapped."

Kamalabob2

Getting advice directly from Q-Con is a good idea. I found their Facebook page and it says that they are " very responsive to messages"

I sent them a message in English and Thai requesting that a technical advisor come to the house and advise my builder. Messenger for Facebook even gave me the opportunity to upload the photos.

Thanks for the suggestion!

We received a very quick reply from Q-Con. They have agreed to come and look at the house and to meet with and advise our builder. Very impressive considering its midnight in Thailand!

[ksamuiguy]

looks like either the water or the sand used to render the walls had salt in it.

[cooked]

I recently sourced some house building materials for my wife who built a modest one bedroom, one bathroom two car garage on her village land. I had Mr. Pitichai of Q-Con provide technical advise to the relatives who had very little previous building experience with autoclaved areated AAC light weight wall blocks. The Buriram Builders Merchants who gave my wife the lowest price on 7.5 thick by 20 cm high by 60 cm long Q Con blocks also arranged technical advise from Q-Con staff. I believe the OP should contact the builders merchant store who provided the Q Con wall blocks and have a Q Con technical advisor go in person to his house in Thailand. The staff I spoke with in April 2015 of Q Con were polite and professional. The OP getting the Thai speaking technical advisor to give real solutions to him and the Thai House Building Contractor for the problem will be of genuine help.

I believe that Eyecatcher has brought up a valid observation: "I think most of these are rain splashes, heavy splashes, the same as you see around most house wall bases. The bottom of the wall is getting splashback and that rain has caused “cheaper” paint to blister.

How did water get in to blister it, well one reason could be the walls were rendered and not allowed to properly dry out before the painter came along; thus the moisture in the render was trapped."

To start: I have built several houses with Q-con type blocks. Blocks that I left laying around in the garden (in Switzerland, -20 °C to plus 40°C, plenty of rain) for years suffered little damage. So no structural damage.

The marks around your house look exactly like the ones on our house and the one next door: rising damp. Your house, like ours, is not built higher than the surrounding ground, and pretty damn certainly doesn't have a damp proof course, which is the first thing you learn when you are a mason. Our house was built conventionally with 7cm concrete blocks.

We have cleaned and painted over twice, as have our neighbours, the problem doesn't go away. Only solution that I have thought of up to now (to hell with French drains): screw aluminium strips to the wall, attach plaster board (with insulation from damp) and possibly stick tiles to that. As with you, we only have this problem in the bottom 40 to 50 cm of certain parts of the wall. so you don't need to do the whole wall, I can live with that.

[fang37]

Not only use Q-Con but the bigger the better. In addition, use Q-Con cement.

[Mike45]

The Q-Con rep looked at the house with our builder. Says its basically rising damp. The Q-Con course should have started 70cm above....the ground level? Or plastic should have been used.

He suggested waiting until very dry, removing paint and cleaning the bricks. Use a Sika water proofing...polymer type on the bricks...not sure of he means directly on the bricks or mixed with new render or both. He mentioned two applications. Then repainting the entire first floor walls of the house.

The builder is also trying to figure out how to keep water away from the walls in the covered outside area..... Maybe install a drain.

My builder has assured me he will get all the work done and will foot the bill for everything.

[cooked]

Waterproofing the surface of the bricks isn't going to do much good if the water is rising up through the wall. You are, according to the fotos, at ground level, so French drains will just collect water which won't be going anywhere but into the wall. A concrete chamber or two somewhere along the drains could be pumped out but are you going to do that every time it rains...? Water from the surrounding soil will happily find its way back into your drains over night. Anyway I am not confident that a Thai builder knows how to install a drain that won't get blocked after a few years due to water carrying gunk into it. You need geotextile, which is available in Thailand but you may have to buy a large quantity.

The Qcon rep. is basically telling you that it isn't his fault, but as I said before, damp proof courses are not a part of building practice here. Starting with the blocks 70 cm above ground would make no difference as water rises through concrete blocks faster than through Q-blocks.

The extension that I built to our house is on a 15cm concrete slab that is above the ground. No probs with the Q-blocks there. The rest of the house is built on a 15cm concrete slab at ground level, with 7cm concrete blocks, and I have problems like yours everywhere. I can't say it bothers me much. The neighbour is going to repaint his house every year.

Live with it?

[lopburi3]

The idea is use sump/sewerage pumps to keep the French drains dry, pumping over ground to the public drains, while blocking any connection below ground to public drains.. It works. And is done full time. And it does not take a very big pump or much power to do so.

[JDGRUEN]

OP -- if you find out the base cause and can do something to remedy that... then for cosmetic and functional repair of the paint ... I suggest using a wire brush and a sander with heavy grit sand paper on an electric sander... Then use a paint such as found in the USA and they have it at HomePro... It is an ELASTOMERIC PAINT ... thick with latex and other tough materials ... One brand in America says ... Exterior Stucco Paint made to withstand 90 MPH wind driven rain. ... The Homepro people will not know they have it ... But scan every can a - some are labeled with big letters ELASTOMERIC ... some small print. You can get it tinted any color you want.

This stuff is so thick that you may have to thin it ... I once covered a shower wall for a temp covering pending tile application ... I took showers and the water did not penetrate - ran right off .... I also used this type of paint only barely diluted with water (as it is supposed to be) and covered a flat roof. This was the same type of application where some use hot or cold asphalt based coverings. This ELASTOMERIC paint on the flat roof ... seeped into all cracks and sealed them and it formed a plastic coating about 1.5 CM thick.... It totally stopped water penetration...

[lopburi3]

Search for that term on there website provides

[alfieconn]

The Q-Con rep looked at the house with our builder. Says its basically rising damp. The Q-Con course should have started 70cm above....the ground level? Or plastic should have been used.

He suggested waiting until very dry, removing paint and cleaning the bricks. Use a Sika water proofing...polymer type on the bricks...not sure of he means directly on the bricks or mixed with new render or both. He mentioned two applications. Then repainting the entire first floor walls of the house.

The builder is also trying to figure out how to keep water away from the walls in the covered outside area..... Maybe install a drain.

My builder has assured me he will get all the work done and will foot the bill for everything.

To be fair to the builder it is the Architect who is at fault.

[Mike45]

The Q-Con rep looked at the house with our builder. Says its basically rising damp. The Q-Con course should have started 70cm above....the ground level? Or plastic should have been used.

He suggested waiting until very dry, removing paint and cleaning the bricks. Use a Sika water proofing...polymer type on the bricks...not sure of he means directly on the bricks or mixed with new render or both. He mentioned two applications. Then repainting the entire first floor walls of the house.

The builder is also trying to figure out how to keep water away from the walls in the covered outside area..... Maybe install a drain.

My builder has assured me he will get all the work done and will foot the bill for everything.

To be fair to the builder it is the Architect who is at fault.

One in the same

[sometimewoodworker]

Search for that term on there website provides

There is also this bitumen paint

If they don't have this brand MrFixit is another one. They are usually black but you can also get a white one in the MrFixit brand

[kannot]

I used stuff similar to this in the UK itd VERY easy and quick to do and works well, you inject into the mortar in the UK this would be the least messy alternative but then i suspect the floors are also scrap too........or will be soon

If you cant get it here you could always fly to somewhere and bring it back in your luggage, its in tubes like silicone rubber, easy to carry

Edited November 4, 2015 by kannot

[Sophon]

I used stuff similar to this in the UK itd VERY easy and quick to do and works well, you inject into the mortar in the UK this would be the least messy alternative but then i suspect the floors are also scrap too........or will be soon

If you cant get it here you could always fly to somewhere and bring it back in your luggage, its in tubes like silicone rubber, easy to carry

This product seems to work by spreading out into the mortar layer, so it probably won't work on walls built with Q-Con AAC blocks since they don't have a mortar layer. If injected directly into the AAC blocks the cream could spread in all directions (and probably mostly downwards due to gravity), and it's unlikely it would create a functional barrier. That is assuming that the cream is able to penetrate the AAC blocks in the first case.

Sophon

Edited November 5, 2015 by Sophon

[kannot]

I used stuff similar to this in the UK itd VERY easy and quick to do and works well, you inject into the mortar in the UK this would be the least messy alternative but then i suspect the floors are also scrap too........or will be soon

If you cant get it here you could always fly to somewhere and bring it back in your luggage, its in tubes like silicone rubber, easy to carry

This product seems to work by spreading out into the mortar layer, so it probably won't work on walls built with Q-Con AAC blocks since they don't have a mortar layer. If injected directly into the AAC blocks the cream could spread in all directions (and probably mostly downwards due to gravity), and it's unlikely it would create a functional barrier. That is assuming that the cream is able to penetrate the AAC blocks in the first case.

Sophon

yes but did they use the proper q con cement? Ive seen some using normal mortar, could try pumping it in at closer intervals.

[fang37]

We used the proper Q-Con cement. No problem.

So it depends on which type of cement is used?

Remedy?

[kannot]

We used the proper Q-Con cement. No problem.

So it depends on which type of cement is used?

Remedy?

if installed correctly q con should have a damp proof membrane installed on the first course.......I wonder if the builder did that or just did the usual shortcut of "nothing"

Id be inclined to hack thru a bit of render somewhere out of sight ( did he use the q con render) and see whats underneath

Edited November 7, 2015 by kannot