Cement pointing on stone walls

[jimmyjamez]

Hi
Just new to this forum and have looked through the numerous similar topics for an answer but I guess, like most, I have a pretty specific question.
We have purchased a c.1700 stone terraced cottage. The walls are stone with rubble infill. It was condemned in the 1960's but rescued by someone who renovated them using materials thought to be ok at the time (concrete floors, cement pointing, plastic based artex extenal render instead of limewash etc. Even though it was empty for a year or so prior to our purchase and there is no heating etc it surprisingly doesn't smell of damp and there are only 2 areas of small damp patches on the chimney breast. I have done some exploratory work (chop away some of the external render, chop out some of the internal cement based pointing) and found no evidence of damp inside the walls. The terrace is built on a rear-to-front slope so drainage is pretty good.

My question is do I need to chop out all of the cement based pointing on the internal walls and repoint in lime. We aim to just paint the stone walls with Earthborn claypaint so the stone should breathe to some extent. It would be great to replace with lime but money and time is tight and will still look the same once painted.

Similarly with the external render. i would love to remove it all, repoint in lime and re-limewash it but would take many, many weekends or lots of money to sort.

The concrete floors should ideally be replaced but no damp appears to be rising up the walls so I question the need to replace these.

Thanks in anticipation
James

 

[Feltwell]

Hi James, and welcome. Hope you've got your camera working as people will start nagging for pictures very, very shortly!

In an ideal world of course your whole house would have been repaired with lime based materials, the fact that it hasn't is very, very common. But, if it's not broke then why fix it? The use of cement doesn't *always* lead to damp problems - and it sounds like that's the case with what you've found.

You stand the risk of causing damage by removing the cement. It sounds like you've taken a very sensible approach - a little chopping out to ensure damp is not trapped behind a seemingly good cement facade.

In your situation I would take the approach of living with what is there for a while and see if you find any problems. If you do then deal with them with lime based materials. I appreciate the desire the re-render the outside and limewash (it does look so much better than plastic masonry paint) but that is something you can come back to when time & funds allow.

Spend a little while in the place and get your ideas together before taking action unless it is urgently required would be my advice. It's very easy to act in haste and then repent later - I re-roofed my house as soon as we bought the place (which did urgently need doing) but in my haste made some decisions which I now regret, having lived in the place for a while.

 

[MdB]

I would agree with Feltwell. The problem with cement is that it can trap moisture. There is nothing to say that it will. If you have little or no issues at the moment then I would live as you are with the knowledge that you know what to do if an problem arises. The one area I would be careful of though would be any woodwork that has been buried in cement as this will be the first to be damaged if there is any moisture present (like the ends of our floor joists...)

 

[worms]

Living in a converted farm building, mine is also a mix of old and new, with concrete lintels and surrounds to the newer window openings and sections where rubble stone has been put back in with cement mortar. No way could all that come out without major works. Property is essentially dry, so no pressure to do anything major. Even the accumulated years of exterior plastic paints are still there, where they have not loosened themselves and parted from the underlying stone and mortar.

But I have been able to use lime mortar to repoint and repatch where necessary - tapping with a chisel tells where it is loose and needs to come off - and the whole lot is now lime-washed, which seems to adhere well to the old snowcem etc. To my eye, the limewash just looks so much softer than the alternatives and is sooooo much cheaper!

I would like to get rid of more of the cement pointing in places - in the attic it is noticeable that when humidity levels are high and it is cold outside, beads of condensation form on the cement but not on the lime - but time, money and priorities preclude anything being done about this.

 

[MatthewC]

Welcome Jimmy. You've already got some good advice above, but I'd just like to echo the worrying thought that, as MdB suggests, there may be damp around that you haven't found yet. There are always things that you discover when you look deeper so don't do things that you don't need to do (I wish I had that luxury!). I suggest you are better off keeping your money, living in the house for a while and seeing what appears.

Matthew
http://houseintheenchantedforest.blogspot.com/

 

[Penners]

Welcome from me too, Jimmy.

I'm another echo of much of what's been said above. Removing cement from a period building can be a solution to damp problems. But if the building isn't damp, then the old adage often applies: "If it ain't broke, don't fix it".

Removal of cement can itself bring problems. Cement often adheres very strongly to the substrate, and its removal can damage that substrate. So it's not a job to undertaken lightly.

Yes, there may be hidden damp in the walls, but if you find no signs of this I should just let the sleeping dog snore on.

 

[AMc]

Welcome! Given the age of the house I'm sure it will show you ways to empty your pockets and fill your weekends
"If it aint broke then don't fix it." If you were to remove all the render or internal wall plaster you should, according to the building regulation insulate the wall. That will be good for your heating costs but can mean you have to change window reveals, extend your roof and all sorts of other things that may significantly alter the house you've bought. So tempting as it may be to hack off modern materials to replace them with good traditional ones, temper that enthusiasm with the phrase "act in haste, repent at leisure".

 

[Feltwell]

If you were to remove all the render or internal wall plaster you should, according to the building regulation insulate the wall.

There is a well known & practised cure to this problem. Don't tell 'em!

 

[AMc]

There is a well known & practised cure to this problem. Don't tell 'em!

Of course you could do that but it's quite easy to start stripping away DIY then when you get a builder involved in reinstating they point out that by "renewing" rather than "repairing" the "thermal element" you are obliged to meet the regulations.

IME Reputable builders tend to have a greater respect for the rules as they need a trust relationship with the inspectors or they aren't able to stay on schedule as they have to keep stopping to arrange inspections.

 

[Penners]

IME Reputable builders tend to have a greater respect for the rules as they need a trust relationship with the inspectors or they aren't able to stay on schedule as they have to keep stopping to arrange inspections.

Quite right. The builder who did a fair amount of work to my daughter's listed building was never once fully inspected by the BCO - the inspections were just a cursory "head popped around the door".

When the BCO came to do his final inspection he said, "This is just a formality - if Paul's done it I know it'll be fine." And it was.

A builder isn't going to jeopardise that kind of reputation.

 

[jimmyjamez]

Many thanks for the advise. I think I will be waiting for a year or 2 to see what the building tells me