Rising damp and damp proofing advise? plastering below the wall and Damp-Proofing Creams

[jibo82]

Hi guys,

So I just bought a house and am busy getting quotes for damp related repairs that needs to be done.

So far Ive had two guys come to give me quotes and they seem to have vastly different opinions on how they will tackle the damp.

The main issue is rising damp all across the house (mostly just exterior).

The first guy says he will dig a to 40cm below the ground and above the ground up to wherever the damage is. He will chop the plaster up to the brick both below and above the ground. Then he will apply some waterproofing layer to the brick, then apply some membrane and then plaster (damp proof plaster) and then apply another waterproofing layer (cemex or something like that). The perimeter walls also have some large cracks which he will patch up the same way include applying brackets to join the cracked walls together where necessary.

The second guy reckons there is no need to go below the ground with the plastering. He say the rising damp is caused because the original plastering was done too deep and is below the damp proof course layer of the floor. He says the plaster acts as a conduit for the water. He will break the existing plaster to the brick up to 30cm above affected areas. He will then add a layer of waterproofing and then plaster (mixing plaster with some compound to damp proof it) and then add another layer of water proofing. I may have missed a few details here. Another area he defers from the first guy is that he will inject a damp-proofing cream into the walls on areas where the damp has affecter the interior walls. The first guy insists that this is ineffective. He will then fix the cracks in the perimeter wall by converting them to expansion joints (shoving slate in between the two cracks or something like that).


So who do I go with. The first guy quoted me 30k, the second 50k. Both seem to know what they are talking about.

What do you guys think about how deep the plastering should be and the effectiveness of damp proofing creams injected into the walls?

 

[krieg]

Hi guys,

So I just bought a house and am busy getting quotes for damp related repairs that needs to be done.

So far Ive had two guys come to give me quotes and they seem to have vastly different opinions on how they will tackle the damp.

The main issue is rising damp all across the house (mostly just exterior).

The first guy says he will dig a to 40cm below the ground and above the ground up to wherever the damage is. He will chop the plaster up to the brick both below and above the ground. Then he will apply some waterproofing layer to the brick, then apply some membrane and then plaster (damp proof plaster) and then apply another waterproofing layer (cemex or something like that). The perimeter walls also have some large cracks which he will patch up the same way include applying brackets to join the cracked walls together where necessary.

The second guy reckons there is no need to go below the ground with the plastering. He say the rising damp is caused because the original plastering was done too deep and is below the damp proof course layer of the floor. He says the plaster acts as a conduit for the water. He will break the existing plaster to the brick up to 30cm above affected areas. He will then add a layer of waterproofing and then plaster (mixing plaster with some compound to damp proof it) and then add another layer of water proofing. I may have missed a few details here. Another area he defers from the first guy is that he will inject a damp-proofing cream into the walls on areas where the damp has affecter the interior walls. The first guy insists that this is ineffective. He will then fix the cracks in the perimeter wall by converting them to expansion joints (shoving slate in between the two cracks or something like that).


So who do I go with. The first guy quoted me 30k, the second 50k. Both seem to know what they are talking about.

What do you guys think about how deep the plastering should be and the effectiveness of damp proofing creams injected into the walls?

That is why older houses have a couple of rows of brickwork and then plastering. I would go with option 3.

 

[jibo82]

That is why older houses have a couple of rows of brickwork and then plastering. I would go with option 3.

There is no option 3

 

[upup]

You just bought the house, did the previous owner knew about this.

 

[krieg]

There is no option 3

Option 3 is to gather more expert advice. I would go with some of what the second guy wants to do but he does seem to treat the problem and not fix it completely. I would also check the slope and water capacity of the ground around the problem areas as well as gutters and roof above.

 

[Kawak]

Depends on whether the damp is traveling up through the plaster or the brick work behind it, if plaster only, option 1 should be enough otherwise you will need to do that injection, my understanding, the injected stuff is a liquid silicon that fills all pores in the wall and seals it, much like tile sealants applied onto natural slate tiles.

Did a fix and sell and the property had a garage that was right against a hill, was the only way to sort out that problem. The wall needs to be dry before that can be done tho.

 

[upup]

I will also go below.

 

[upup]

Depends on whether the damp is traveling up through the plaster or the brick work behind it, if plaster only, option 1 should be enough otherwise you will need to do that injection, my understanding, the injected stuff is a liquid silicon that fills all pores in the wall and seals it, much like tile sealants applied onto natural slate tiles.

Did a fix and sell and the property had a garage that was right against a hill, was the only way to sort out that problem. The wall needs to be dry before that can be done tho.

also try some draining pipes

 

[Kawak]

also try some draining pipes

If the plot has very high water table, proper inspection by a hydrologist may be needed with a plan for proper management. The row of houses in my area, right up against the waterfront literally needed underground hydrological work, when it pours, water seeps out their lawns. The water table in my area is very shallow, plus side, we have plenty of borehole water.

 

[jibo82]

Depends on whether the damp is traveling up through the plaster or the brick work behind it, if plaster only, option 1 should be enough otherwise you will need to do that injection, my understanding, the injected stuff is a liquid silicon that fills all pores in the wall and seals it, much like tile sealants applied onto natural slate tiles.

Did a fix and sell and the property had a garage that was right against a hill, was the only way to sort out that problem. The wall needs to be dry before that can be done tho.

The plaster does seem to be wet at the affected places, Im not sure if the brick is too. Yes, the cream they inject works as you stated.

 

[jibo82]

Option 3 is to gather more expert advice. I would go with some of what the second guy wants to do but he does seem to treat the problem and not fix it completely. I would also check the slope and water capacity of the ground around the problem areas as well as gutters and roof above.

The roof seems fine. There are no gutters...yes




The part in the blue box is the patio and it has a flat roof that doesnt seem to have been maintained since it was made. So the whole waterproofing at the top needs to be stripped and replaced.

The part in the green box seems to have been a later addition and the floor does not seem to have a damp proof course layer beneath it and is the worst affected part in the house.

There is evidence of a half-assed damp repairs around the house.

The part between the pool and wall of the house seems worst affected. The area with the loose stones looks like a place where water will just sit.

 

[Geoff.D]

Don't just treat the symptoms. Find the source of the water first, fix that then do the wall work. And yes you should not plaster the wall below the damp course layer --- it is always a problem and will remain a problem forever.

As per one of the previous posts, check your roof, the gutters etc. Eliminate that as a source of the water. Then get in an expert hydrologist to help diagnose the groundwater issue. THEN only do something about the walls. And you will never solve the problem while the walls are wet. -- This is dry season job.

 

[RedViking]

You are not going to be able to do anything about it unfortunately, for a permanent fix.

The DPC is probably damaged by now. DPC cant be below ground. Plaster should not be below ground as well.

DPC must also "step" down from inside to outside. But who knows what builders are up too.

 

[Lupus]

There is no gutters, the water from the roof is just running off there, that could cause the issues, gutters could be done to redirect the water away properly.
The roof doesn't seem to overhang far enough for the water to run away from the wall.

 

[jibo82]

Don't just treat the symptoms. Find the source of the water first, fix that then do the wall work. And yes you should not plaster the wall below the damp course layer --- it is always a problem and will remain a problem forever.

As per one of the previous posts, check your roof, the gutters etc. Eliminate that as a source of the water. Then get in an expert hydrologist to help diagnose the groundwater issue. THEN only do something about the walls. And you will never solve the problem while the walls are wet. -- This is dry season job.

So I don't think there are major structural issues. The house is almost 30 years old. It "seems" the main culprit is the shoddy modifications (patio, extra corridor by the front door, the pool, lack of slope on the space between pool and the house etc.) done to the house. I am looking into eliminating the sources of water in the affected areas.

 

[jibo82]

There is no gutters, the water from the roof is just running off there, that could cause the issues, gutters could be done to redirect the water away properly.
The roof doesn't seem to overhang far enough for the water to run away from the wall.

Yes, I will be adding gutters. Its strange that they chose to omit that...perhaps aesthetic reasons?

 

[RedViking]

Yes, I will be adding gutters. Its strange that they chose to omit that...perhaps aesthetic reasons?

Very common it seems among homes with concrete tiles. Not very clever.

 

[Geoff.D]

Yes, I will be adding gutters. Its strange that they chose to omit that...perhaps aesthetic reasons?

I call it Architectural Stupidity Syndrome. (ASS) Yes. The science of building a house is so well known, yet more and more you see even the most basic of rules just ignored. Aesthetics and keeping up with the Jones' overrides common sense.
Good idea to add gutters. That will keep the water away from the area around the foundations.

 

[RedViking]

There is evidence of a half-assed damp repairs around the house

Which might have been a top quality fix...... but it won't work.

Lol, ain't I a happy guy.

 

[RedViking]

I call it Architectural Stupidity Syndrome. (ASS) Yes. The science of building a house is so well known, yet more and more you see even the most basic of rules just ignored. Aesthetics and keeping up with the Jones' overrides common sense.
Good idea to add gutters. That will keep the water away from the area around the foundations.

Stupid Client and Builder Syndrome.

Go look at the Architectural drawings. It has gutters.