rising damp

[dr mendit]

We are in the process of buying a terrace (2nd from end) 1920's house in Whitstable, Kent. We had a full homebuyers survey, which found a problem with rising damp. The damp patches are situated mainly in the back dining room on the rear wall at ground level, on the chimneybreast and on a solid dividing wall with the lounge!! In places the plaster is crumbling and there is evidence of white crystals (look like salts). The bottom 2 feet of the wall dividing this room with the lounge have been re-plastered and had new skirting fitted. The new plastered area is ok but just above it the plaster is crumbling and damp patches exist.

We are currently enquiring with the agent if any damp remediation (injection or new dpc) has taken place and will be enquiring with the neighbours if they have any problems with damp! The house also has a few damp patches in the lounge neighbouring wall and kitchen solid dividing wall with the dining room. Concrete floors exist throughout the ground floor (which seem OK). The rear wall is of a cavity type and has recently had new air bricks installed!! The rear patio is only one brick below dpc and has very little fall away from the house!! The chimney openings in the lounge, dining and rear bedroom have been boarded up and have plastic vents on them. All the rooms have vinyl looking wallpaper apart from the rear dining room (the main problem room).

We had a damp proof company come in for opinion and price. He says its rising damp with evidence of salts (proof of rising damp). He quoted £9000 excluding VAT to tank the whole of the downstairs with John Newton NEWLATH 2000, which is a breathable membrane. The walls would then be dry-lined, plaster boarded and plastered throughout.

I was expecting some kind of rising damp solution in the problem areas NOT tanking throughout the whole downstairs. Needless to say he won't be getting the job and I have decided to tackle the problem myself.

I want treat the dividing wall to either a solid dpc or injection dpc. Also, I want to check the rear cavity wall for bridging and if necessary rake out the cavity, lower the ground level at the rear to 2 bricks below dpc and provide a gravel border between house and patio. I want to open up the fireplaces and install a wood burner in the back room and strip all the wallpaper and paint walls with a breathable paint.

Any thoughts on the matter would be appreciated.

 

[breezer]

been mentioned just a few times before, try a search on rising damp, but i will start you off with this one

 

[dr mendit]

i have read around the subject including your link thankyou

 

[dr mendit]

The neighbours recently told us that the house was built on a flood defence and that the stream at the end of the garden was converted into a culvert to control water entering the local homes.

The only problem I will have a problem tackling is inserting a dpc into the partition wall. From looking at some of the postings I want to avoid injection dpc and opt for the traditional type 'plastic dpc'. The problem is how to get the dpc in.

Has anyone had experience of using bolts and acro's?

 

[timmyquick]

I my self did what you want on a wall in my house that is to put in plastic dpc. I did this on a 9 inch solid wall gable end by taking three bricks out at a time, lay the dpc for 2 bricks left the roll inside where the 3rd brick previously was, laid the 2 new bricks with mortar and left for 3 days to harden. This takes an extremely long time and i would have never done it on a party wall i just don't see how your neighbours would give you permission to do it and if it is only a single brick party wall your stuffed unless your neighbours don't mind having a great big gaping hole into your home. At least you could pass the sugar when one of you is short.

 

[masona]

The problem is how to get the dpc in.

Are you saying you have no dpc at all ?

Also have you look at "French Drain" to keep water away from your property ?

 

[dr mendit]

I like the one about the tea. The neighbours were quite friendly when we met them, perhaps we could have a tea hatch! No really the house is terraced and has a slate or bitumous dpc back and front (seen from outside).

The party walls either side are one brick length deep with some damp areas. The main damp however is on the single brick dividing wall between our lounge and dining room. Does anyone know if these walls should have a dpc (house built c. 1920). Anyhow, I am thinking of inserting a plastic dpc in the single brick wall. Your right Timmyquick I could never put a dpc right the way through the party wall. It would mean work on both sides. I am thinking of using a chemical injection on the party walls!! Was then going to tank the walls with NEWLATH OR OLDROYD breathable membrane and plasterboard.

Also found out the other day the suspended floor was removed and replaced with concrete so this could have ascerbated the damp problem (the penny never dropped when I saw the air bricks outside)

 

[oilman]

I am thinking of using a chemical injection on the party walls!!

That'll smell a bit until the solvent dries. Will your neighbour put up with it?

Also found out the other day the suspended floor was removed and replaced with concrete so this could have ascerbated the damp problem (the penny never dropped when I saw the air bricks outside)

Seems the solution is to get some airflow past the wall then. I wonder, from this, if your idea of dpc injecting the dividing wall is a good idea.

If you go back to the beginning, the house was built with suspended floors. The airflow would have removed the moisture from the wall which must have come from the ground, and you say the house is in a low lying area. The wall has thus been keeping the water level under the house under control. You now have no underfloor space and no way of getting rid of moisture before it gets above floor level. If you stop the moisture getting up the wall, it can't get out of the ground. Will this cause another problem?