for People with a Passion for Period Property
Ask an Agony Uncle!
Stephen Boniface - Stephen Boniface specialises in building conservation providing multi-disciplinary consulting services. He is Chairman of the Building Surveying Faculty and member of the Residential faculty. He serves on the RICS Building Conservation Forum Board and is the 'Agony Uncle' on the Period Property UK website (

Ask our Agony Uncles ...

You can write to our panel of experts free of charge on any subject, providing it's got something to do with Period Properties.

Our experts are all specialists in matters directly involved with older properties. So, if you have a problem with an older building - or if you think you might have a problem - ask an Agony Uncle...

o Poor flashing leads to water ingress Mike Foster (Greater London)
o Earthy smells cannot escape from rooms Nigel Pearson (Shrewsbury)
o Professional advice to stop weathering of stone Stephen Cooper (Somerset)
o Traditional limewash provides better solution than PVA Tony Corr (Warwickshire)
o Official advice required before change of use Sandra Evans (Gwynedd County)
o Conservation requirements make roof ventilation difficult David Ramage (Dumfries and Galloway)
o Roof insulation also requires ventilation Andy Haynes (Oxfordshire)
o Asbestos tiles lead to possible concerns Julie Revans (Bristol)
o Don't hide damp deal with it at source John Albury (Gloucestershire)
o Underpinning leads to insurance problems Stuart Bell (Somerset)
o Crazy cracking requires raking & filling Sidney Jevons (Wiltshire)
o Potential purchaser faced with cannibalised stone barn Name Withdrawn (Cornwall)
o Removal of concrete screed reveals brick floor Rob & Katie Blair (Leicestershire)
o Hi-tech imaging equipment can reveal property's structure. Nick Bell (Cambridgeshire)
o Iron stains on lime walls John Galloway (Highlands and Islands)
o Can I insert a dpc in clay lump? Chris Groves (Norfolk)
o Towering Chimneys provide home for giant birds Elisa Smith (Lincolnshire)
o Lime Source Tracy Knight (Hampshire)
o Stripping in front of the fireplace Janet Shaw (London)
o Local conservation officer should have the contacts Hugh Zocher (London)
o Dusty pamments need more appeal Stephen Clabburn (Brundish)
o Sources of salvage in London Lisa Reynolds (London)
o Quarry tile floor needs sparkle Ainsley Williams (Worcestershire)
o Dirty limewash in cellar Bryan Sadler (Lancaster)
o Cob shows signs of wear & tear Louise Farrand (Dorset)
o Listed building planning permission required Chris Walsh (Clwyd)
o High ground levels cause penetrating damp Jeremy Bullock (Berkshire)
o Damp floor may lead to un-doing of previous work Claire Greene (Buckinghamshire)
o Timber floors need sprucing up Anna Erken (Gloucestershire)
o How far should I go in removing internal plaster? Alec Gunner (Cambridgeshire)
o Lime source Alison Burleigh (East Sussex)
o Crumbling Cobble Martyn James (East Sussex)
o Metal framed windows cause dilemma Lee Pearce (Essex)
o Stain barrier Mary Page (Lincolnshire)
o Have we really got rising damp Sonia Fagan (Norfolk)
o Use of mastic in timber frame house causes alarm Philip Degg (Staffordshire)

SUBJECT: How far should I go in removing internal plaster
FROM: Alec Gunner (Horseheath, Cambridgeshire)
We live in an 1870s former schoolmaster's house, red brick with all the classic faults leading to rain penetrating in small, isolated patches (cement repointing with no backing mortar behind it etc.). I'm dealing with re-pointing in lime and filling the holes in the backing mortar but the problem is what to do inside. The walls still have their original lime plaster, but this has been skimmed with gypsum twice, once in ~1950s and again last year (just before we bought it). This has been painted with a vinyl emulsion. Where water has been penetrating the lime plaster is weakened (hollow when tapped) and the surface is stained but the overall surface is flat due to the skimming. So my question is, how many of the incorrect layers should I try to remove and how should I go about it with minimum disruption to the original lime plaster underneath?

Alec Gunner

Alec, it depends on what you are trying to achieve. Firstly, if you are trying to achieve a genuine breathing wall where internal moisture is absorbed into the fabric of the building and then simply evaporates away then the internal skimming needs to be removed. Normally, once you are behind the skimming it is fairly easily removed. Simply tap the surface with a hammer, then use a bolster chisel to get behind the skimmed plaster. One of the other benefits of having a traditional lime finish internally is that you can either limewash or use a distemper on the walls. Once the skimmed plaster is removed it may be possible to simply screw any loose areas of plaster back into place without disturbing the entire surface before further patching. Alternatively, undertake the external repairs as stated and simply wait to see if your damp problem goes away. The fitting of a decent extractor fan in both the bathroom and kitchen will help reduce internal levels of moisture considerably.



SUBJECT: Lime source
FROM: Alison Burleigh (North Chailey, East Sussex)
How can we re-point our old flint cottage? The original mortar is lime. If we need to use lime mortar, can you suggest where we can buy it ready made?

Alison Burleigh

Alison, before embarking on such a project can I suggest you contact The Lime Centre in Winchester, Hampshire on 01962 713 636 who run 'Lime Days' which will provide you with the basic skills to undertake such a task. They also supply the necessary materials, but an alternative source would be Chalk Down Lime Ltd in Hastings who can be contacted on 01424 443 301.



SUBJECT: Crumbling Cobble
FROM: Martyn James (Finchley, London)
The front wall of my house is cobbled and is beginning to crumble. Can you suggest the best way of tackling the job? It seems to be the outer shell of the 17 inch wall that is affected.

Martyn James

Martyn, contact the Lime Centre in Winchester on 01962 713 636. They run weekend lime courses which will provide you with the necessary skills to undertake the repairs. The raw materials can also be purchased from the centre.



SUBJECT: Metal framed windows cause dilemma
FROM: Lee Pearce (Colchester, Essex)
I live in a 14th Century cottage. My property has leaded windows, although with solid panes of glass. Two have cracks in (one my fault !) and the glass needs replacing. The larger window, in my kitchen is also rotting. All of the windows have metal frames and the bottom part of the kitchen window frame is the worst. What should I do and who should I contact please ? The property is listed so I assume I will have to stick with the same style windows. Also, I wonder whether secondary glazing would be possible in my house but don't think a regular window company could help. The outside of my house was decorated just before I moved in 1996. The paint is showing signs of wear and has come away in one or two places, exposing red brick that appears quite soft and crumbly.

Lee Pearce

Lee, before moving onto the repair of your metal windows can I suggest you read the following article by Peter Clement, the chairman and MD of Haslemere Ltd, a leading renovator of traditional metal windows. The article can be found on and gives a review of the historical development of metal windows as well as a general guide to their renovation. To find a reputable specialist in your area who can deal with the repairs contact the Steel Window Association on 020 7637 3571. I would imagine such a specialist should be able to provide some assistance on the secondary glazing front. And, of course, because your property is listed I would imagine your local conservation officer would insist on the repair of the windows rather than their replacement with a potentially new style in a different material.

Finally, I would imagine your property has been painted with a modern paint which may be trapping damp in the brickwork of the property. It may be worth taking some specialist advice regarding the potential removal of the paint and repair of the brickwork. Ensure any advice sought is from a conservation accredited RICs surveyor.


SUBJECT: Stain barrier
FROM: Mary Page (Lincolnshire)
We have bought an old, semi-derelict cottage that has been the home of an old man who smoked for many years! In one particular room the ceilings and walls are brown from the tobacco, and although it is the original plaster, it was emulsioned at some stage. How can we remove the nicotine staining? In another room that was not quite so bad, we had to put in a false ceiling as the stains kept showing through when we emulsioned. We cannot do that in this room as the ceiling slopes down to join the eaves. That is why we have left this room until last to renovate in the hopes that a perfect solution would come to hand. Do you have one please?

Mary Page

Many builders would advise you to use diluted PVA glue which would effectively seal the surface of the ceiling in question, but impact on its natural performance by restricting the evaporation of any damp from the fabric of the property. A possible solution is to use a Swiss paint called 'Classidur'. The paint has excellent stain covering ability, high vapour permeability and comes in matt or a satin finish. Contact Blackfriar on 01275 854 911 for a local stockist and remember only purchase a small or trial tin first which should be test-coated on a small area first.


SUBJECT: Have we really got rising damp
FROM: Sonia Fagan (Cawston, Norfolk)
We have rising dampness in the living room of our 1800 cottage and are getting a recommended company to insert the dampcourse. What I'm worried about is the replastering. They are supplying a salt-inhibitor to mix in with the materials, but what materials should be use - or more importantly what materials should we definitely not use?

Sonia Fagan

Sonia, I feel you should be concerned with not only the plastering but the whole concept of rising damp. Please read the following article by the Sunday Telegraph journalist Jeff Howell on


SUBJECT: Use of mastic in timber frame house causes alarm
FROM: Philip Degg (Knightley, Staffordshire)
We have a half timbered cottage, which was partly "restored/rebuilt" by former owners about 30 years ago. We want to treat the external exposed timbers as they are showing signs of rot in places. Some of the beams appear to be structural, and they look OK, but some look like they have been treated and put back for effect, as some appear actually hollow/very gnarled, and couldn't possibly be structural (we hope). They appear to have been painted with a bitumen or heavy black stain, don't know if we can stain over this? Also, the edges against the panels have got a mastic sealant which has started to come away. We are looking for advice on whether we need simple cosmetic "touch up", or severe structural change!, but are really struggling to find anyone to help and advise.

Philip Degg

Philip, firstly it is important to stress that the strength of timber used in old properties derives from the heartwood and not the softwood. Therefore the surface of a stud or beam can look in an appalling state yet still have its strength uncompromised. Secondly, you are quite right to point out that the use of a mastic sealant is inappropriate for an old property. The use of the mastic may have been used for numerous reasons such as the prevention of rain penetration, the infil of gaps between the timber frame and the daub panels or even to hold the panels in place. But for whatever the reason the use of a mastic sealant is only likely to lead to problems as it prevents panels between the studs from breathing. Finally, to remove the heavy black stain on the timbers contact Strippers on 01787 371 524. Then visit and under the directory section click on either surveyors or builders to find someone in your area with the necessary knowledge to advise you on the condition of your property.