Damp Walls in terraced house.So, how do I get rid myself?

Frank_Sebem

Hi all

I just bought a terraced house (in the middle of the Block, not an end House) that is obviously suffering from damp.

On the front of the House there is 1 downstairs window, 1 entrance door & 1 upstairs bedroom window.

I have diagnosed damp because of the following symptoms:

External rendering has fallen off
Underneath and around windows on the INSIDE of the House the plaster has fallen off and is also, damp with Black Mould spots.
Further along the wall, the Plaster inside the House is very crumbly. I had already resigned myself that a few rooms would need replastering anyway, so I could do with some advice how I can combat this damp myself, or is a Job for the professionals? The reason I ask if it's possible for me to combat the Damp myself is because I'm sure I have seen kits etc in B&Q of something like Silicone that you squirt into the Brick after you have drilled some holes about 3 bricks up. Am I right? Is there a product I can buy to do this myself??

Thanks all.

MaggieBaking

Professionals. You're at a risk of the damp getting worse, causing more structural problems, and ruining everything you own like your mattresses and clothes.

MRSTITTLEMOUSE

We did a damp treatment ourselves before moving into our house almost six years ago and it's been fine.
There was realy bad rising damp too.
My husband used "ultracure" damp proofing cream we bought it on ebay.
It was cheaper in bulk from there and arrived within 48 hours.
Thats the easy bit ,injecting the cream in but you have to replaster too.
We saved a lot of money doing it ourselves but if you're no good at plastering you'll need to get a plasterer,thats an expense you can't save on I'm afraid.

thedeester1

If the house is rendered make sure it doesnt start at ground level it acts like a sponge. The render should start at least one brick above ground level. Next check that the garden or yard hasnt been rasied above floor level in the house. Ive seen people have lovely block paving but its not been dug in deep enough and water soaks through the wall into the plaster. In the same way make sure thet no one has blocked up any air bricks. Lots of old houses had coal cellars or raised floors. Ive known people cap the "Coal Hole" and seal it up nice. This stops rainwater comming in but also stops the cellar "airing". As its below ground level and they were (very) rarely tanked in the old days this adds to the damp problem. Get some air into the cellar or underfloor if possible.

Check the guttering and run offs. One simple proplem is that spouts are missing from the end off fall pipes on the guttering. The water runs down the pipe then just pools right up agaist the wall. Just adding a spout and diverting the majority of the water away from the wall gives the wall time to dry out.

Some old walls just seem to hold damp no matter what you do. I had a corner house with Stone corners and one of these just seemed to hold water. It was 3 feet above ground level and just left a black square on the wall in the shape of the stone. The only way I got it controlled was by re-plastering with Revovating plaster. It was quite expensive and didnt completly fix the problem. Still had to paint over the damp bits once every 2 years but at least there wasnt a permanent black square.

If all this fails you need the damp proofing pros.

craigsville_2

From a lot of experience with damp victorian houses (im not a damp specialist though!), here are a few points.

1. what caused it? either no damp proofing (lots of old houses use a slate course), render to the floor bridging the damp proofing, soil level around the area raised bridging the course etc.

2. The biggest cost is replastering as once you solve the problem of damp, the plaster will all blow anyway and need replacing, is it cost effective to risk doing it yourself, get it replastered(the biggest cost) and then have to do it all again because its not done properly?

3. You will need to look at all ventilation as well, air bricks etc.

4. How high is the damp? rising damp wont be very high up, ie if its upstairs then its not rising damp, its a leaky roof/guttering/pointing etc.

My first port of call would be a free quote from a few damp specialists who will have a look, see what the problem is, give you a quote. If you fancy doing it yourself then work out the cost of treatment/replastering and see if its a big enough difference for your time, effort and no guarantee. Hope this helps!

Frank_Sebem

Hi all

Thank you for your advice. It seems the problem could be a combination of things.

1. The external Rendering (that has now fallen off half way up the walls) goes very close to the outside pavement. I can't see any drill holes UNDER the bottom (where the render finishes), so I'm guessing the render has bridged the damp and allowed it to rise from the floor into the rendering and up.

2. The window has been poorly measured & fitted. There is an inch gap (filled with expanding foam) all around the window.

3. The property has been unoccupied for at least 6 months.


I have read LOADS of pages of stuff about Damp etc and a lot of pages & people point to faulty guttering. Would somebody PLEASE explain how a faulty/leaking/damaged gutter or drain could cause damage to walls, especially at the bottom of the House. By this I mean...surely, if a gutter was damaged or faulty Water would just P*** down the walls thus letting us know it was damaged?? Do you mean that Water is running down inside the cavity?

Another thing to note is... Where the render has fallen off the outside of the Building (underneath & around the front window) the Bricks are badly detoriated for about the bottom 4 courses. When I say deteriotated I mean they are powdery etc and go to powder if you rub them with your hand.

Gmitch2000

Here is some info from a company doing some damp work for me.

Rising damp comes from the ground but penetrating damp can come from gutters, etc.

A GUIDE TO DAMP

GENERAL INFORMATION

Rising damp is caused as a result of water migrating through the capillaries of the materials with which most
buildings in the UK are constructed. This primarily will be either stone or brick, and other regionally-used
materials of construction, as well as substances which are used to bond these substrates together. These
include mortar (which can be in varying types of mix including sand and cement), ash and various other
materials which have been used throughout the centuries. Water can travel through these capillaries to a
height which will be determined by the narrowness of the capillary tube. The narrower the capillary tube, the
greater the height reached. To overcome this problem in new constructions, a physical damp proof course is
installed at roughly 150mm above the external ground level. This prevents the rise of water within the wall by
breaking down the continuity of the capillary action. Over a period of time this damp proof course can break
down or become breached, allowing moisture to rise up the wall through capillary rise (i.e. rising damp.) Rising
damp causes damage to interior plasterwork and can soil decorations. It shows itself by causing wallpaper to
peel and paint to blister. These problems are often made worse by the appearance of efflorescing salts on the
surface of the wall. These salts, if deliquescent or hygroscopic can make matters worse as they will extract
moisture from the air and into the problem of surface dampness.
It is important to treat rising damp. The physical deterioration it causes, and the costs involved in remedial
work are problems enough, but it should also be noted that a cold damp property is an unhealthy environment
and is also expensive to heat. Problems can be further aggravated by rising damp as it can cause other
associated defects such as dry and wet rot, which once established, can spread over a wide area and become
both destructive and expensive to eradicate.

Penetrating Damp

Penetrating damp is usually a result of building defects, such as cracked and defective external rendering,
damaged and defective rainwater goods, (i.e. downpipes and gutterings), leaking roofs, high external ground
levels and badly fitted or rotten joinery.
The penetration of moisture through external walls at low level can often be confused with rising damp and
care must be taken during an inspection to accurately identify all building defects that may be contributing to
dampness within the property. Again wet and dry rot attacks are often instigated by external defects, allowing
water to penetrate the fabric of the building.

Hygroscopic Salts

Hygroscopic salts are a symptom of rising damp and have the ability to trap moisture and will also be present
following damp proofing treatment, e.g. the new damp proof course which has been installed. These salts will
remain unless they are also treated as a separate problem. They are often the result of rising damp and on
completion of damp proofing treatments in the property, the moisture which is already above the level of the
new damp proof course will in time evaporate, but whilst this process occurs, salts in the fabric of the structure
will be carried to the surface of the wall at times of high humidity. There are various chemical types of salt
which come from different sources such as unwashed building sand, contaminated masonry and substrate
from agricultural buildings that have been converted into living accommodation. There are also salts within the
ground. Existing plaster work which is contaminated with salt must be removed in conjunction with damp
proofing treatments and this is the reason why replastering is always necessary upon completion of damp
proofing treatment.

Condensation

Condensation can be a major problem in buildings of modern construction which are not adequately heated
and ventilated (heat and ventilation being the key to control the effects of condensation). Condensation occurs
when warm moisture laden air lands on cold surfaces. The point at which condensation occurs is referred as
‘the dew point’. The dew point is more usually reached on cold surfaces, but in some circumstances, the dew
point occurs within the fabric of the porous substrate where the resultant condensation is referred to as
interstitial condensation. In normal modern living we produce a considerable amount of moisture within our
homes by simple everyday living, for example bath/showers, cooking, the drying of clothes and even breathing
are a major contributing factor towards condensation. The symptom of condensation is the appearance of
unsightly black mould growth, which will appear on wall surfaces, furniture and even clothing within wardrobes.

TREATMENTS

The installation of a new damp proof course is designed to create a continuous barrier throughout the length
and width of the wall to reduce the capillary rise of moisture. More common methods of damp proofing
treatments used by Rot & Damp Solutions are as follows:

Silicone Injection

Aqueous based silicone fluid is injected under pressure, having the effect of reversing the meniscus in porous
masonry. Once installed, the siliconate prevents moisture from rising within the capillaries, creating a new
damp course.

Injection Cream

This is the very latest in damp proofing technology utilising a concentrated cream for the control of rising
damp. The cream is delivered by hand pressure and migrates rapidly into the masonry pores.

Electro-Osmosis

The use of electro-osmosis has particular advantages in stone walls and walls of greater thickness. The
system introduces a very small and perfectly safe electrical current into the wall just above ground level. It’s
effect is to repel the rising moisture molecules down the wall and harmlessly back into the ground.

Mortar Injection

The mortar injection method uses a specially formulated dry mix of cement, quartz and reactive chemicals.
Once mixed with water, the chemicals released react to form a crystalline growth, which penetrates and blocks

the capillaries, pores and fine cracks within the mortar.

Leif

I would go for an independent specialist who has no financial incentive to diagnose a particular solution. Then when you get his report, commission a damp proofing company to do the work if any. There is no such thing as a free lunch, or a free survey. Mould does indicate damp, and around windows suggests damp penetration around the frame, or perhaps condensation if the area around the window frame is below the dew point i.e. cold. It is not unusual for plaster to blow and deteriorate. My 1960's house had many areas of blown plaster. Similarly I guess render could fall away due to weather but that is an uneducated guess and you need a specialist to check.

There is one test that might work. I had damp concrete floors, which dried when uncovered, so I taped down large squares of foil making sure the edges were dealed. I also put down some carpet tiles. The next day the floor under the carpet was damp, whereas that under the foil was dry. That proved that the damp came from the room, not the floor i.e. condensation. You could try the same trick with your walls. Maybe nonsense, but it costs little to try.

robert2011

Hi Frank, my guess is your house was built in the 30s ? i think your walls do not have a damp proof course ? If so ! go to your local plant hire and get a liquid compressor injector for rising dampness. You drill holes into the mortar not the bricks every 200mm and insert the nozzles this injects a silicon into the mortar bed creating a damp proof couse.
Do this to all the ares you have problems with. DIY it or pay £2000 cira

Norman_Castle

External rendering has fallen off
Underneath and around windows on the INSIDE of the House the plaster has fallen off and is also, damp with Black Mould spots.

The render fell off beneath my second story window. This was caused by a leaky window frame. As you say your window appear badly fitted this may be the cause.

The window has been poorly measured & fitted. There is an inch gap (filled with expanding foam) all around the window.

Is expanding foam waterproof?

Frank_Sebem

Thanks for the advice Peeps. I've thanked you all by clicking thanks.