Oh my word...what are we doing?

[learner]

Hi everybody

My wife and I are about to take a rather expensive plunge and could really do with some advice please :? . The Surveyor's report has just come back on a 200 year old yorkshire stone cottage and as expected there is penetrating and rising damp in most of the external walls and also in some of the internal ones.
Externally, the stonework appears to have been pointed with a cement based mortar. Some of the penetrating damp is due to identifiable problems on the roof and eaves, but the surveyor also believes that it is seeping through the porous stone walls which in some areas are only 9" thick. Internal walls are mainly dry-lined (in one case with asbestos sheeting!!) The previous owners have had chemical damp-proofing injected into the base of most of the walls 12 years ago - this now appears to have failed. The floors of the 2 worst affected rooms are concrete with a (partially) fitted damp membrane.

I have read the other threads about damp in old buildings and I understand the view that walls should be allowed to breath with traditional lime-based materials. However, my surveyor has recommended further chemical injections, new concrete flooring with (complete) membranes and a silicon application to the outside of the walls.

Right, here are the questions:

Why is there such a difference of opinion concerning damp treatment in old buildings ? (ie between the 'let it breath' approach versus the 'keep it out' techniques)

Should the fact that this building has already had 'modern' techniques applied (albeit unsuccessfully) affect my approach to solving the problems? Can I switch to 'old' techniques?

If I re-point externally with lime-based materials, should I do it all in one go or only when patches need to be repaired?

How much is a limecrete flooring? Are there any cheaper alternatives to a breathing floor?

Grateful for your help...stress levels have risen since the report arrived :shock: !!!

Rob

 

[Nemesis]

Oh dear - lousy surveyor with no idea about traditional buildings, see sticky at top of the page...

 

[Gervase]

Most surveyors are trained on 'modern' houses; those built post-1914. As such, their advice is tailored to buildings with cavity walls, cement foundations, damp proof courses and the like. The majority have no idea about traditional buildings, but nevertheless continue to profer the advice they would give for a modern house.
Sadly, most people take the surveyor's word and carry out such work, which is invariably to the detriment of the building.
There's nothing to stop you switching to traditional techniques, but it is best if you undo the modern 'remedies' first. This means removing cement pointing and render, reinstating proper ground levels outside, using lime rather than gypsum plaster and having a breathable floor without a membrane.
The price of a limecrete floor depends on the size, but for the average cottage you're probably looking at around £2500.
And, for what it's worth, I would bung the surveyor's report in a drawer and bring it out in years to come for a laugh. It's hardly worth the paper it's printed on.

 

[Nemesis]

Unless it has now gone to a mortgage company...

The floors - they might once have been suspended wooden ones? In all probability once flagstones of course, laid on earth.

 

[Penners]

The previous owners have had chemical damp-proofing injected into the base of most of the walls 12 years ago - this now appears to have failed.

If it ever worked in the first place.

Why on earth does your surveyor feel that a damp treatment that either didn't work or quickly failed the first time should be repeated? Sounds like throwing good money after bad, to me.

 

[Nemesis]

It's cos it's all he knows. The idea of painting the walls with silicone is a very bad one too.

I'd ask for my money back!

 

[learner]

Hmmm...thanks for your thoughts....I thought that might be the response :lol: I will challange the surveyor tomorrow and see what he says (and report back to you for interest). The firm have a good reputation and are they used to project managing the renovations of older buildings so it will be interesting to hear his view.

A couple of further questions if I may.

If you use traditional methods, I presume that you accept a degree of moisture in the walls - how does that affect the timbers set into the masonry? Is there not a risk of rot and later failure?

Also, what do you think of the use of french drains - there is high ground to the rear of the property and a trench alongside the rear aspect but currently covered by flagstones. Owing to a parallell road that runs very close to the house at the rear, any new drainage would have to run alongside the rear wall and then away from the corner....would french drainage be useful in this situation. I'm not sure how deep the foundations are but bearing in mind the rather thin walls they may not amount to much so I would be concerned about inducing movement if I dug too deeply.

Rob

 

[Nemesis]

The firm have a good reputation and are they used to project managing the renovations of older buildings so it will be interesting to hear his view.



That doesn't mean they do them with any sympathy at all or knowledge of appropriate techniques.

In fact, it sounds the opposite.

I'd get in someone who can give sound advice - did the surveyor have any conservation quialifications? I'd ask ...

http://www.ihbc.org.uk/Downloads/Education_papers/EG_1_Summary_10_November_1B.pdf

Traditional techniques - it's how places were built, and in general have served them well. Yours has been standing 200 years. Of course there will need to be some renewal at times, things don't last forever. However. too often the use of modern techniques and materials has lead to rapid acceleration of decay and caused major problems - the use of cement mortar, for example, can cause terrible damage to stone and brick.


http://www.spab.org.uk - worth joining.


Yes French drains are useful, but not in all situations can they be installed. If that's the case there are other methods of dealing with damp penetration when ground levels are high.

 

[Penners]

If the adjacent road still leaves you enough space to have a gravel-filled French drain along the back (uncovered, to allow free air circulation) this could well be of benefit. Given the high ground level there, it could also be worth putting a perforated pipe into the bottom of the French drain, and running this away to a soakaway.

 

[chuckey]

Penners reply has promted me to wonder about french drains. The most common use for them is to drain fields/motorways, so the capital cost must be minimised, while for a householder the cost of the digging will probabley be the major one. Likewise Penners comment about the gravel filled drain to promote evaporation. Unless the water in the bottom of the drain gets heated or the saturated vapour gets blown away, I am not sure that leaving them open is such a big deal.
What I am postulating is that both ends of the drain are vented to atmosphere, one vent being at the biggest height that is convenient (roof height?). My theory behind this, is the gopher vents its under earth runs by this method, though its vents are just little molehills of 2" height or none. When breeze occurs, the pressure differential between the two different vent height will positively drive air along the drain, speeding up the evaporation of the water.
Any comments?
frank

 

[Jill]

We thought we had a major damp problem on an internal stone wall which is 18" thick until we found this site and did a bit of reading. We had been told of a number of alternatives which we could try to remove the damp - injection, trenches, some kind of electrical device. It turns out, after I did a test square, it is just the wallpaper, paint and plaster that are damp and the stone and the muck filling it are quiet dry. Here are some photos to try and reasure you that it might not be as bad as you first think. We are in the process of chipping all the render off so that the stone will be exposed. The wall looks worse because of years worth of Pauls nicotine! Most of the fireplace has been removed.

Half way up photo on right hand side shows the damp - this is right along the wall

After removal of wallpaper, flaking paint and plaster.

The muck between the stone is dry

Work in progress - we just need a couple of rainy days so we can't work outside so we can get started again.

 

[learner]

Thanks very much for your remarks everybody and your reassurance Jill (those beams look great !) I am open to all ideas, but I do like balanced arguments and to hear the pros and cons of the various options open to me especially when it concerns something I don't understand a great deal . I think I now have a good idea about the disadvantages of modern techniques for dealing with damp, but could somebody tell me what disadvantages there are to using traditional methods? There must be some surely? A balanced argument perhaps :wink: . Thanks for your help

Rob

 

[Nemesis]

Well many of us who post here have some experience and a spot of expertise in dealing with period buildings, and have also experienced first hand the damage wreaked to traditional buildings by those who haven't a clue. Many are having to undo misguided work. Sadly sometimes the damage isn't possible to really undo - walls ruined by cement pointing, that sort of thing.

Not sure that there is a much of balance really... bugger it up or do it properly.

Here's a major expert on the subject:

http://www.ribabookshops.com/site/viewtitle.asp?pid=3928


French drains: a bit of reading:

http://www.ihbc.org.uk/Technical%20Papers/French%20Drains.htm


And a bit more from the sainted Brian Morton:

http://www.ihbc.org.uk/context_archive/47/columns_dir/columns_s.htm


I like this:

Repairs to historic buildings should only be undertaken and supervised by those with appropriate expertise, craftsmanship, respect, skills and appreciation of history and beauty and commitment to the fundamental principles of conservation. Many builders (and some professional advisers) do not have the necessary skills, expertise or knowledge. When seeking estimates or tenders for work a properly detailed specification and schedule of works should be provided by an experienced conservation architect, surveyor or other suitably skilled adviser.



which is from here:

http://www.eastherts.gov.uk/index.jsp?articleid=2582

You might find this organisation useful:

http://www.yvbsg.org.uk/


And of course the local authority:

http://www.northyorks.gov.uk/public/site/NYCC/menuitem.72980bf1db3dfb9fd7428f1040008a0c/?vgnextoid=6f8873409b3eff00VgnVCMServer0d6519acRCRD

 

[Fizzer]

It sound like you're in exactly the same position that we are in. Cement rendered walls, concrete floors, high ground levels and rising damp. We have an understanding surveyor who has pointed us in the right direction.

We have also had 2 seperate experts telling us to do the injection/dpm work.
We only used the quotes from them to reduce the price of the house. Now we are older and wiser (by a month at least) and will probably burn the quotes to heat the house.

We're planning initially to:
ventilate and heat the house -gas CH -open up the fireplace -free up painted shut windows
Let the walls breath -strip the modern paint and plaster downstairs
reduce lateral water penetration -dig a french drain

All of this can be done by us and friends (apart from the CH) and is non destructive to the fabric of the house.

IF this doesn't help significantly, we're may end up removing the concrete floor and replacing with limecrete. I think that this may be much further down the road though.

We've come to realise that we don't NEED to fix everything straight away, you can relax and enjoy your house while you work on it. Ours after all, was occupied by an octogenarian for many many years so it can't be all that bad

 

[Nemesis]

Fifteen years down the line and we have hardly scratched the surface beyond making some rooms habitable! Thankfully the mortagge will be paid off in the next month - something it seemed when we started out on the road to homeownership decades ago would never happen... and that frees up cash to get serious things done like the roof. Yippeeee!!!!

But hey - the sun is shining, the garden is growing, and I'd rather be in my period wreck, with always something to plan and work on, than in a modern finished box on some ghastly national developer estate.

 

[learner]

Nemesis - I am convinced !! Thanks very much for those links - there is an excellent article about Lime on the local authority link above.

Fizzer - you're dead right...our situations sound exactly the same, and I am at the stage of trying to get a price reduction based on the survey...we shall see.

As promised yesterday, I asked the surveyor about his views on traditional techniques and he admitted to being a fan...so why wasn't it in his report? He did say that his recommended use of silicon wash on the exterior stone was only a short-term palliative and that traditional techniques would probably be better in the long term. Shame that wasn't in the report, but at least he acknowledged it verbally.

 

[Nemesis]

Yes, it's pretty good stuff:

http://www.northyorks.gov.uk/files/NYCC/Directorates/Environmental%20Services/Historic%20building%20advice%20-%20512/Lime%20Mortars.pdf

Jane Schofield, whose little book on lime is avaiable from SPAB and frequently recommended here.

The pictures are very persuasive... ;-)

Well if he knew why on earth didn't he say...

 

[Penners]

the sun is shining, the garden is growing, and I'd rather be in my period wreck, with always something to plan and work on, than in a modern finished box on some ghastly national developer estate.

Hear, hear!!

By the way, are you able to see the sun from inside the house, or only outside?

 

[Nemesis]

When I clean the windows I can...

 

[Penners]

I was thinking more about the roof...!