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Damp Proofing Questions

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866 Questions: Damp Proofing


Rendering over DPC.

Hi there,

I have a house that was built around 1890 and is of brick construction with a rendered band running around the base which also forms square edged columns around the front door. Until recently the house had a concrete front garden that met the building at the level of the base of the grille ventilating the ground floor cavity.

I have removed the concrete slab as it was falling toward the building and was, I thought, too high in relation to the ventilation grille. Removing the concrete slab exposed the DPC visible at the level of the base of the grille. To be 'belt and braces' I removed the render one course above the dpc and injected Dryzone into the mortar joint.

My questions are
- if i lower the new front garden level to 150mm below DPC im going to be very nearly on top of the brick tier foundation, is this a problem
- I want to reinstate the render band as all the other houses have them and it also forms part of the elevation detailing around the front door, but have read that the render shouldnt go past the DPC. If i stopped the render above the DPC and dropped the ground 150 i'd be left with a band of fairly tatty looking bricks that have been underground for the last 40 years. How could I finish this without compromising the damp proofing?
- should I install a french drain of some kind?

Many thanks for your help!

Yleoric66 8th May, 2013 Damp Proofing
1 Answer u1

I having my wall damp proofed from penetrating damp but it looks like they have left a section.

Due to a recurring leak which has now been fixed i decided to have my walls damp proofed. They took the wall back to the brick work and have applied a render coat of washed sand and cement to a wood float and then applied a membrane of Triton TT55 or something similar. They are going to plaster over it but before i speak to them about it and in case they try to baffle me with science i wanted to ask for some advice. they have left an area of brick exposed in the top right corner near the ceiling, it hasn't been covered with any thing. The brick is still showing and looks like its crumbling. Now if they just re plaster over it, is there a chance the damp can come back through. I am unsure as to why they would damp proof the rest of the wall and not that section. Its part of that section which was most affected by the leak. Can anyone help? ps it comes with a 10 year guarantee.

Yjuliao 17th Apr, 2013 Damp Proofing
1 Answer u1

damp to front elevation

i think my driveway may be causing damp. How can i tell if the damp course is bridged? Its edwardian with skirt/plith at bottom of wall. Looks like the ground has been raised and a dpm laid uner the crazy paving and right up to the skirt/plinth. Is it possible to deal with this without taking the whole drive up? Did think about lowering the ground around the perimiter of the house but might end up with trench like and fill up with water. Not sure where i go with this - any help welcom.

Yrenogirl 7th Apr, 2013 Damp Proofing
1 Answer u1

damp problem

i have a ground floor flat. boys bedroom external wall down at skirting area has a damp area in corner of room. have looked outside and no wet area ie gutter or leak from gutters etc. any ideas or solutions

Ytoh13 14th Mar, 2013 Damp Proofing
1 Answer u1

Builder cut through DPM

I have had a two storey extension built. There was a misunderstanding with one of the young lads on the site, who cut through the damp proof membrane with a stanley knife - to 'make it look neat'. There is now a gap left, where the dpm is cut off level with the floor base, and the dpc. Because the house is quite low down, the exposed brick became wet when it rained over the weekend. As a fix he painted the exposed course of bricks with Wickes damp proof course. When it rained, this became wet, and obviously wasnt up to it. To further repair, he has now glued membrane to the top layer dpm, and glued this to the wall, bridging the dpc. My question is, beacuse this is glued to the top dpm, can moisture now go in between the two dpms, i.e. into the insulation layer? If so what would be the result? I am thinking of re exposing the trimmed off lower layer of dpm myself (I've lost trust with his workmanship), and gluing a new strip to it to extend it up against the wall above dpc layer, and fix it against the wall with plaster. Any advice? Does that sound like a good course of action to take? Also - should i re trim the top dpm back to the height of the slab so that air can get down into the insulation layer?

Ymr_anonymous_xyz 13th Mar, 2013 Damp Proofing
1 Answer u1

What order to do things in? Damp before Electrics?


We have just bought a Victorian terrace in need of some work. It requires a full rewire but it also has damp.

We have a small amount of rising damp, but a basement that we have been recommended to have tanked with SIKA. In addition to this part of our kitchen wall is below ground level and recommendations have been to treat up to 1.9m with waterproofing (although not SIKA).

We need to do the damp quickly (to claim back a mortgage retention) but have no idea whether to do this first or get the electrics done as not sure which is more invasive. Concerned that if any parts of walls need to be removed for the rewire that it would cancel our damp guarantees.

Any advice very much appreciated.

Yevamay78 13th Mar, 2013 Damp Proofing
1 Answer u1

im getting damp patches on my outside wall just above skirting boards

im in a end terreced house and upstairs in my bedroom im getting damp patches just above my skirting boards???

Yfliss_80 6th Mar, 2013 Damp Proofing
1 Answer u1

Outside yard higher level than house?

I'm purchasing a house, and the survey has recommended the outside yard (which is concrete) be lowered, as it is now slightly higher than the utility extension [outhouse-style construction] and is causing some rising damp to the utility and adjoining dining room.

How would one go about this, and is it a big job - would extensive damp coursing be required, and would there be damp still in the floor for some time, as I'm assuming even after lowering the level, the structure that is damp will need to dry out? Thank you.

Yfirsttimebuyer22 6th Mar, 2013 Damp Proofing
1 Answer u1

passyfier vents

can one fit a passyfier vent in a timber framed building?

Ytonyraymond 26th Feb, 2013 Damp Proofing
1 Answer u1

Damp area on wall

We recently moved into a 1920's property which we have started renovating. After stripping off the wall paper back to plaster in one bedroom and have noticed that on the outside wall, there are 2 patches where the plaster feels almost soft to touch/springy and slightly damp/moist. One area is around the top of the wall before ceiling level and the other is about half way down the wall.
The other 3 walls have been re plastered but have held off with this wall as we are reinstating the fireplace but want this possible issue resolving to avoid any hold ups when the builders arrive to work on fireplace.
Any advise would be greatly appreciated.

Ybecky_ward 25th Feb, 2013 Damp Proofing
1 Answer u1
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