Hi
Looking for some advice. I live in a victorian property with solid 9″ walls. We have damp coming in on the two front corners of the house. There are no salt marks that seem indicative of rising damp. However on the outside at these two points the dpc has been bridged with either a concrete ramp (access to the garage) or step to the front door. We have had damp proofing contractors qoute who have either recommended doc injection or cdm system. Costs from £1600 upwards. Totla area that will require treatment is 5m2. No one has mentioned removing the point source i.e. Removing the points at which the dpc is being bridged. I think im being ripped off a little in that the treatments being recommended will only mask the problem, the treatments will still result in damp entering bricks that will/may long term result in damage to the bricks and finally if the route cause is removed then additional specialist treatment will not be required, only remove old damaged plater and replaster? Any help /advice much appreciated. For information, i am based in Reading so south east prices cold be a factor.
Cheers
Ernie

Read this.

http://www.heritage-house.org/managing-damp-in-old-buildings.html

Or this…

https://www.spab.org.uk/publications/old-house-handbook/

Good advice from Cougar and slowoldgit, bricky myself do work on old properties working with lime mortars etc. Identify yourself a specialist in renovation in your area, you are bound to have a heritage centre nearby or at least at the end of the phone, SPAB for instance…

I would advocate removal of any cement render or pointing and reinstate with replacement lime equivalents.

MUTDz

Difficult without pics but can’t you just cut back the step/ramp to create a gap, say 100mm wide and see if that helps? You might be able to fill it with pea shingle.

Good point Squirrel, pics?

Would a victorian property have a dpc?

Slate used in some cases or non-porous engineering bricks, the link from cougar shows the latter.

MUTDz

Would a victorian property have a dpc?

Possibly slate, although no signs of one on our house (no damp either).

or tar painted onto brick course as a dpm at appropriate level

chemical DPCs or electrolysis things are snake oil. Address potential sources of damp and use lime mortar.

Is it damp or condensation caused by the higher ground / colder spots?
Definitely sort the step and ramp out so that they don’t touch the house

My Victorian house suffers on one wall, in particular corner. Why? Because it’s exposed to the weather and gets cold. Interior is warm. Condensation forms and settles at the base of walls.

The house was converted into two flats, I’m upstairs and not as bad as downstairs flat gets it. Sadly previous owner got conned by the fraudsters and now there are injection holes. New owners complain about damp still.

What sort of decorative finish is on the wall? Modern vinyl paints can cause issues in properties that were designed to “breath”.

Address potential sources of damp and use lime mortar.

This.

Manage water and allow move and not gather.

Address how water is entering if due to an addition like the ramp and make sure the walls can breathe properly – inside and out.

Used to have a Georgian flat and it has been painted on the outside and several attempts (before I had it) to try and use silicone injection in the walls.

Stripped back, installed a breathable membrane slurry and then lime plasters. Addressed any outside sources by stopping water pooling against the outside, entering from broken guttering etc and installed a french drain = lovely warm flat that felt healthy and no more mould. (sadly couldnt remove all the external paint as it was job too far)

Thanks everyone. The room was wood clad, this looked fantastic but masked the problems. DPC seems overkill as the walls are not wet, plus it does not solve the root cause. I think I need to remove the pathway first and foremost.

Ernie, let the air get to it, by the sound of it you have or are about to remove the panelling so thats good. With the house being properly occupied and the heating on this should balance out the temperature differentials and aid the drying process.

As I and the other other guys have said above look at remedial work on the points where the original damp course has been bridged, if a step or ramp is still needed it does not have to necessarily be physically connected to the building at that point to function (ie you could leave an expansion or movement joint) between the fabric of the wall and the step/ramp.

The mortar joints on the brickwork will be lime based due to the age of the property. As we have all advised do not let yourself be tempted to use cement mortar as this will, 1 likely be stronger than the brick work when set and 2 be impermeable to water so condensation moving out through the brick will be slowed by the cement and exacerbate any damp issues, as well as making the brickwork which will be holding the moisture susceptable to frost damage (+ erosion) if it is in an exposed position to the weather.

Using cement mortar on older materials does not fulfill what should be a sacrificial role when considering erosion from weather. Mortar joints should never be stronger / harder than the brick or stone that it is bonding together. The idea is that the lime mortar allows free transfer of moisture and erodes out leaving the brickwork predominantly intact, all then that is needed is re-pointing decades after construction or repairs.

For extra satisfaction, study the form on the above mentioned sites and consider taking time out to do it yourself if you have the time. Just take your time with it.

MUTDz

Cheers dude