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Damp Proofing Questions

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903 Questions: Damp Proofing


Lightwell Drainage

We are having a lightwell created in our front garden to create light in our basement. We have been offered 2 options RE drainage and I'm not sure which one makes the most sense...

1. Cast new 150mm concrete floor slab incorporating natural drainage pipe work encased in pea shingle with a plastic outlet gully.

2. Drain the water into the Cavity Membrane system of the basement (not fitted yet) and get rid of it that way.

RE option 1 - Would this pea shingle drain work like a french drain? Would it be at the foot of the house where it meets the light well floor?

And which option do you think is best and why?



Ymcampster 3rd Oct, 2013 Damp Proofing
1 Answer u1

RICS surveyor indicated high damp readings in exterior facing walls

I'm about to move into a property, my RICS surveyor indicated high damp readings in most exterior facing walls. Some of the plaster seems to have flaked off or appears to be crumbling.

It is 1900 cottage with 'no obvious DPC' according to his report.

Naturally I'm thinking to hack out the plaster, chemical injection DPS, replaster - HOWEVER: the property has never had central heating, has poor insulation and has been heated with mains Gas Fires in all rooms.

1) Could this be the cause of dampness? - in which case:
2) Should I just sand down the plaster, install CH and see what happens? or
3) look at DPC, even though I'm reading a lot about cowboys and Damp Proof being a myth...?

Help - I'm confused. Thanks!

Yadamsurrey 19th Aug, 2013 Damp Proofing
1 Answer u1

Persistent damp patch in kitchen

I wonder if anyone can help please. We had our kitchen plastered 6 years ago, there was a patch by a small window which took much longer to dry than the other walls, eventually it dried and as advised by our plasterer, we used a base coat of 1/2 water 1/2 emulsion and then two coats of kitchen/bathroom paint.

About 2 years later an area by the window started to bubble, we sanded it down, applied damp proof paint and then kitchen/bathroom paint and this seemed to solve the problem.

However about 6 months ago the same thing happened but it affected a larger area, once again we sanded the area, applied damp proof paint but mistakenly applied as a top coat ordinary matt paint. The paint we used is a very light colour and the affected area never seems to dry.

In the meantime we have had the exterior of our house painted and all cracks filled. Near the affected area there is a small extension housing a toilet and a back door into the garden. When the painter was painting the outside of our house, he mentioned that there were no lead flashings on the roof and he had sealed the roof where the tiles meet the apex with sealant.

We have pulled up the floor boards on the upper floor to see if there are any pipes leaking which could cause the damp patch in the kitchen but there appears to be nothing leaking. Can anyone help please. Thank you in advance.

Yjan_pearson 19th Jul, 2013 Damp Proofing
1 Answer u1

Damp proof course not working. Can we do it again?

We have done a damp proof course without success but we have a new plaster. Can we do a damp proof course again without removing the plaster? And which way of damp proofing should we use?
Thank you.

Ycharlyne 25th Jun, 2013 Damp Proofing
1 Answer u1

House smells strongly of damp - what needs to be done?

We're looking into renting a 3 bedroom, 2 storey, carpeted house that has been vacant for a month. The entire property smells strongly of damp. There are fine cracks in the ceilings/paint, black spots and ebbing patches on walls, ebbed up linoleum flooring in the kitchen, dark patches on walls and ceilings, and condensation on the windows. The landlord says they would have someone come apply damp proof to a 2nd floor corner that has damp, but that little more than paint is needed. What repairs would actually need to be done to the property to rid it of the damp signs/smells?

Thank you!

Edited: There's an extraction fan in the bathroom, but no fan in the kitchen... also there are 4 chimney breasts that have been blocked off, but no vents. Also, the house is set into a hillside, so the back garden is tiered above the level of the ground floor of the house...

Ybalamire 21st Jun, 2013 Damp Proofing
1 Answer u1

damp on party wall - do I really need a survey

Hi. My son has just bought a house, a 1930's semi, and damp meter recordings showed some damp present. The only visible signs of damp are some peeling of wallpaper and signs of mould extending a few inches at most above the skirting board along the party wall with their neighbour. I am not sure if this is historical as it does not feel damp, or particularly cold even, to the touch, and interestingly, the cupboard on this wall has no signs of damp in it at all. There is no smell that we have noticed and the skirting boards look fine. I do not want them to get a free survey as I know these firms sometimes recommend damp course insertion etc afterwards when this is not necessarily the answer. Of course, they want to start off on the right foot with the maintenance of their property but want to spend their money wisely. Also, I am wondering what a survey would involve as they have laminate floors, the lifting of which would of course be a problem. Advice please!

Yellie_55 30th May, 2013 Damp Proofing
1 Answer u1

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
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