Damp proof course, replace bricks or render with cement?

Thunderbird_2

Hi

I am in the process of getting some work done to my house. The bricks below what you expect the damp proof course are severley weathered.

The question is, what are the pros and cons of replacig the bricks with layer.sheet proofing vs rendering the over the brickwork with injection damp proof?

Many thanks

bobinbognor

You don't say if the damp course is intact or damaged or if the brickwork above the damp course is damp or dry.
If the brickwork above the dampcourse is dry then the membrane is doing it's job and rendering over the outside of the lower courses of brick would be acceptable but don't take it above the line of the damp course membrane. If the bricks are wet and crumbly you might have to replace some, get a bricklayer in to have a look.
If the dampcourse membrane is damaged, missing or has never been there then you could replace the membrane or inject a suitable fluid. Again get a local brikky in for a look-see!

Thunderbird_2

Thank you for you reply.

It is not clear if there a damp proof course around the property. Some areas seems to have it others don't. I had a pamd proofing guy looked at it and he said it has got some areas of damp that needs injection in certain areas of the internal walls of the house. Bricks below what should have been damp course level are severely weathered, but, the ones above are in a good condition.

A bricky said he can do either replacing the bricks below the damp course and install a memberane, or render over the existing bricks after injecting them. He said the choice is mine, hence the question!

Thank you for taking the time to reply and looking forward to your advice.

iamcornholio

No render or coating should bridge the DPC

Any render applied below the DPC will fall off quite soon as the damp pushes it off when frozen.

Replace any damaged bricks, don't bodge them up

David_Aldred

Hi,
Preferance is to replace the damaged bricks below the damp proof course (dpc) level with sound second hand bricks to match surrounding brickwork and during this work ensure any cavities within the external wall are clear of debris to below the lowest dpc level. If the dpc is damaged then inserting a new pitch polymer sheet dpc during this work (if this is possible) will provide a superior barrier to true rising dampness. Kindest regards, David Aldred Independent damp & timber surveyor

knowloads

You could use a lime render like decopierre and have brick look added to match, or a plain finish to look like a strip of stone.

Johnjohn

If the bricks below the DPC are more damaged than those above the DPC it is a sign that the DPC has been doing its job. It is difficult to tell without a photo, but I'd speculate that the weathering is called by spalling. This will be worse on the bricks below the DPC because they are damp (most spalling is called by expansion and contraction of water as it freezes and melts). If the DPC is doing its job, the bricks above won't be damp as much of the time (obviously they will become damp when it rains, but they won't be PERMENANTLY damp) so they will suffer less from spalling.

Thunderbird_2

Thank you all for your replies.

Render is out of the equation now as it might looked at unfavourabley by surveyor should I want to sell the house in the future.

The builder now suggested to replace all the bricks below the DPC, by removing them at short alternate interval and using NEW engineered imperial bricks. This will leave the house wall with new bricks at the bottom and old ones above DPC.

Is it possible to get second hand engineered bricks to match the ones in the house, or is it ok to use the brand new ones? Which is better in adding/preserving the house value if wanting to sell in the future? Any other considerations?

Many thanks

sukieinthedesert

Best to get professional advice as you do not want to bridge a working damp course. I would call an independent surveyor and ask his/her advice. If they recommend any sort of treatment avoid a company called Kenwoods. They have just done an incredibly bad and expensive job on our house. We had to call them back twice to finish the job and their plastering is so bad that we then had to call in a plasterer to re-skim so that we had even walls. Our terracotta floor in the kitchen was destroyed and now has to be restored at our expense. Spilled chemicals, gouges, broken tiles etc. We had to move out while they worked and I nearly wept when I saw what they had done. Appliances that we were assured would be carefully removed had been dumped in the garden and then replaced before the plastering was done so they were covered in plaster. I found bits of my fridge all over the garden. Complaints have been ignored as they take the money up front and as we were abroad for a lot of the time they had free hand to destroy, skimp and try not to do all of the work contracted and paid for. We eventually got all the work done by threatening them with court. Not nice people.

carrieisgreat

i agree with the post above.... they were rubbish on the job they did for me..... definitely avoid. I can show you photos- post back if you want to see!

G_M

Thunderbird wrote: »

..... I had a pamd proofing guy looked at it and he said it has got some areas of damp that needs injection in certain areas of the internal walls of the house. .....

So basically this was a salesman for a dp company? And he suggested injection damp proofing? Presumably this is a treatment that his company offers?

Surprise!

Far better to maintain your property properly.
* replace damaged bricks (reclamation yards will sell you used ones
* repair poor pointing
* forget rendering - what purpose does it serve except to retain damp behind it?
* ensure existing dpc (nearly all houses have them) is undamaged) (suspended floor inside? lift boards and inspect external wall from inside)
* ensure flow of ventilation beneath suspended floor inside (blocked air bricks?)
* ensure nothing breaches the dpc