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 (www.periodproperty.co.uk).

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 Does a Traditional Brick Floor laid on Earth Lead to increased Damp Rachel Elliott (Suffolk)
o Frost Damage to Bricks Sarah White (Durham)
o Waterproofing Solution on Bricks may Cause Further Damage Paul Forman (Berkshire)
o Lower External Ground Levels Helps Alleviate Damp Richard Goodyear (Isle Of Wight)
o Timber Frame Advice Michael Westrop (Essex)
o Removing Pebbledash to Solve Dampness Maureen Wilkinson (Norfolk)
o Once Perfect Chimney Smokes us Out Allegra Amati (London)
o Woodworm in Roof Timbers Anita Omatseone (Yorkshire)
o Leaky Chimney Flashing Robert Goodwin (Cheshire)
o Flagstones May Still Require Some Elbow Grease to Clean Steven Cenci (Essex)
 

SUBJECT: Does a Traditional Brick Floor laid on Earth Lead to increased Damp
FROM: Rachel Elliott (Sudbury, Suffolk)
I have recently bought a 16th century cottage and have started to make some renovations, one of them being the removal of a 1940's fireplace. We also took up the hearth and discovered under a concrete screed what we assume to be an original floor of Suffolk yellow bricks. On removing the carpet we discovered damp which appears to have come through the concrete. We started to remove the concrete very carefully with the intention of cleaning the bricks and leaving them but I am now concerned about damp. The bricks are set directly into the soil and I really do not know what to do for the best. If we seal the bricks will it create a problem? Can we leave them set straight into the ground? As half the floor has been uncovered I am in need of some help fairly quickly.

Rachel Elliott

Rachel, the problem you have described is common amongst many period property owners. Years ago the idea of having a brick floor was perceived as antiquated and unfashionable. This led to many traditional brick floors being covered with a thin layer of concrete, followed by lino, then further in the future, carpet. Such a move simply resulted in ground moisture being trapped beneath the concrete which then gradually migrated to the property's walls instead of naturally evaporating through the joints of the brickwork. In a timber framed property this would result in the decay of the soleplate. The simplest solution is the remove all of the concrete, then let the floor dry out, and experience first hand if the problem you have described with damp continues. If the bricks are damaged or you find the unevenness of the floor a little tricky you could attempt to lift the bricks and bed them in a new layer of lime mortar, but be warned any attempt to lift the bricks is hazardous as they do tend to break when levered from their lifelong resting place. I would also strongly advise you not to use any waterproofing solution on the bricks or install a new concrete floor with dpc. Both methods may result in an increase in the moisture levels in the surrounding walls and increased dampness. Therefore, your first step is to expose the floor, repoint the joints between the bricks with lime, then sit back and live with it before deciding to seek further advice and undertaking any other expensive work which is more suited to a modern property.

 
 
 
 

SUBJECT: Frost Damage to Bricks
FROM: Sarah White (Durham)
We are in the process of purchasing a brick Edwardian house on a hillside in County Durham. We have be told that the brick work has extensive frost damage and that we need to render the walls. Is there anyway of protecting the brick without covering it up?

Sarah White

There are a number of issues here. Who told you that the bricks are suffering frost damage? How extensive is the damage? What type of bricks are they? What is the mortar mix? It may be that the bricks have suffered damage and are vulnerable. However, to cover them up or to treat them inappropriately could cause more harm than good. The problem should really be assessed by someone with local knowledge of bricks used in the district, who will take a sensible sympathetic view. It may be that localised repair and repointing will suffice. You may have to consider some form of protection, which could take the form of a 'shelter coat' of limewash. The important thing to remember is that to use anything that is in any way impervious or not properly breathable could result in trapped moisture and an increase in frost damage, etc.

Period Property UK would like to thank Stephen Boniface Associates for answering this question. Stephen Boniface can be contacted on 01279 421 509

 
 
 
 

SUBJECT: Waterproofing Solution on Bricks may Cause Further Damage
FROM: Paul Forman (Wokingham, Berkshire)
I live in a 1740's Grade II listed property - it needs minor repointing work on the house and rather more on the high garden perimeter wall (which may need replacement red rubber "battered" bricks) - I have also been advised to apply K501 masonry waterproofing solution to the house walls to minimise water splash and ingress - have you had experience of this as a product and are the results favourable?

Paul Forman

Whilst I personally do not know the product you mention this is primarily because I have an aversion to using a modern 'treatment' to seal brick walls in old houses. Most old brickwork is porous and is meant to be. More importantly, the mortar was originally a lime based mix and the wall was 'breathable'. Moisture that penetrates the outer face of the brick evaporates freely during wind or dry weather. The pointing tends to act as the 'lung' of the building and should always be slightly softer than the brickwork. It is the pointing that should be sacrificial not the brickwork! To 'treat' the walls goes against the principle of breathability and usually causes more harm than good. If you have a genuine problem of water ingress then look to see why, because the building would not have had the problem originally. Most dampness problems can be traced back to changes that have occurred or neglect of basic maintenance. Without seeing the brickwork I cannot advise further, but I strongly advise against the use of a 'waterproofing solution', especially on soft red bricks, as the medium to long term result will be damage to the brickwork.

Period Property UK would like to thank Stephen Boniface Associates for answering this question. Stephen Boniface can be contacted on 01279 421 509

 
 
 
 

SUBJECT: Lower External Ground Levels Helps Alleviate Damp
FROM: Richard Goodyear (Isle Of Wight)
We have just bought a 300 yr. old cottage made out of Isle of Wight stone. On the outside the ground level is higher than the inside level. I would like to dig it out to normal ground level. Do you think its wise to do as my partner believes it may damage the stone work. We also have damp on the inner wall.

Richard Goodyear

One of the most common causes of dampness in older buildings is that the ground level is too high. Over the years the ground has been allowed to build up against the wall. Ideally, the ground level should be at least 150mm below the internal floor level. Without seeing the problem I cannot advise specifically, but it seems that the most sensible and cheapest solution might be to simply excavate the high ground around the bases of the walls. Make sure you do not undermine what footings/foundations might exist (if any)! Rather than create a channel it is preferable to lower the ground for some distance away from the building. However, if a channel has to be formed, make sure it is well drained (do not back-fill it with shingle as this defeats the object of clearing away the ground!). Exposing the base of the wall will allow moisture to evaporate lower down, before it can get high enough to cause damage. Do not treat the walls with anything other than traditional breathable finishes such as limewash. To function properly the wall must be able to breathe.

Period Property UK would like to thank Stephen Boniface Associates for answering this question. Stephen Boniface can be contacted on 01279 421 509

 
 
 
 

SUBJECT: Timber Frame Advice
FROM: Michael Westrop (Finchingfield, Essex)
We are about to purchase a particularly old house, in need of considerable renovation. It was originally a hall house, possibly dating back to the thirteenth century. We are quite well informed about timber framed buildings, but know less about properties this old. Can you suggest sources of information and good advice?

Michael Westrop

Essex County Council have a Historic Buildings Department and they are an excellent starting point. The Conservation Officers are friendly (usually!)and are very knowledgeable. They also run regular courses at Cressing Temple. You could also contact The Society for the Protection of Ancient Buildings (SPAB), who have a technical adviser, publish several leaflets and run occasional courses.

Period Property UK would like to thank Stephen Boniface Associates for answering this question. Stephen Boniface can be contacted on 01279 421 509

 
 
 
 

SUBJECT: Removing Pebbledash to Solve Dampness
FROM: Maureen Wilkinson (Norwich, Norfolk)
There is damp in the back extension which houses the kitchen and a breakfast room. We spent the summer chipping rotten plaster and cement render off the internal walls (which we have left to breathe' behind the units), and filled three skips with concrete from the adjacent back passage. While we were at it, we lowered the soil level there to expose a couple of extra courses of brick. The outside is pebble-dashed. Would it help if we hacked this off up to about 4ft and (assuming the bricks will look awful afterwards) tidied things up with a lime render and lime-wash?

Maureen Wilkinson

The simple answer is yes because initially this will allow any trapped moisture to escape and evaporate away, but you will eventually want to provide an appropriate finish to the wall surface. Was the building always pebbledashed? If so, you may need to investigate the precise form of pebbledash and look to re-forming it. Whether it was or not, it is likely that the building had some form of protective covering. This could have simply been limewash or a form of render. Lime is not as simple a product as many would believe. There are many forms, some of which behave in a way not too dissimilar to cement (but it is not the same as cement!!). We now know that our forefathers understood these differences and used different forms of lime for different applications. Whether you reform pebbledash or eventually hack off the pebbledash to form a different finish, make sure you understand the product you are using and that it is appropriate for the job in hand.

Period Property UK would like to thank Stephen Boniface Associates for answering this question. Stephen Boniface can be contacted on 01279 421 509

 
 
 
 

SUBJECT: Once Perfect Chimney Smokes us Out
FROM: Allegra Amati (London)
WMy mother has an old cottage in Gloucestershire which used to be an inn. We have now had the cottage for about 15 years and up until now, we have been able to have a gorgeous roaring fire in the sitting room. However my mother had an exposed corner, repointed and since then it has been impossible to light a fire ( the chimney is situated near to the repointed corner of the house). Every time we light a fire, there is a good pull, but smoke pours out into the room, making it impossible to stay there. We have had the fireplace in the room directly above sealed and we have had expert after expert and chimney sweep after chimney sweep in, and all to no avail. It remains a mystery and no one can understand it. Have you ever heard of such a problem, or do you know of anyone? We are all missing the cosy fires that we once had. Please help, a house isn't a home without a roaring fire.

Allegra Amati

Whether the repointing is associated with the other problems is the first thing to establish. Did the room previously have draughts and the repointing has cured this? If so, the problem could be related to a lack of air supply into the room. If this is the case you may have to find some way of introducing a fresh air supply to the hearth area. I assume the chimney has been swept and the flue generally checked? As well as the normal 'hot air rises' principle, a chimney relies on a difference in air pressure between the bottom and top, the bottom having a slightly higher pressure than the top, hence the smoke rises up the chimney. When smoke pours down it is usually because the pressure difference is insufficient. Sometimes it is necessary to bring the base of the flue lower by installing a hood (this effectively lengthens the flue). I of course assume we are talking about a large 'Inglenook' style fireplace. The Fireplace Association should be able to advise, they used to publish a number of useful leaflets. In the first instance see what happens if you open a window. If the fireplace then works it suggests that you need to improve the fresh air supply to the hearth. If this does not work, or you still get a problem, try installing a temporary hood (metal) to see if this works.

Period Property UK would like to thank Stephen Boniface Associates for answering this question. Stephen Boniface can be contacted on 01279 421 509

 
 
 
 

SUBJECT: Woodworm in Roof Timbers
FROM: Anita Omatseone (Kildwick, Yorkshire)
I have recently purchased a Grade II listed cottage. A recent inspection of the roof space has highlighted evidence of woodworm that looks to have eaten up to 1/2 of the thickness of the supporting timbers. The wood is very soft and quite damp (due I expect to there being no felt under the stone tiles). What action is required?

Anita Omatseone

I suspect that you need do nothing. You do not say if the timbers are softwood or hardwood - this is very important! If softwood or some forms of hardwood, the damage could be more serious than if the timber is Oak (very durable). Is the damage recent or historic? If historic, there is no need to do anything, as the timbers have stood the test of time with the damage. If recent, there must be a reason. You suggest the timbers are damp, but why? Most historic roofs have no lining and this is usually beneficial, as it allows good natural ventilation, and most overlapping roof coverings have no need of a lining. You need advice from someone experienced in looking at historic buildings, someone who will not be fazed by the sight of a few woodworm holes. From what you say the worst-case scenario could be that the roof frame requires strengthening and targeted treatment (of active infestation) needs to be undertaken at the same time. By the way, the best time to undertake treatment is in the late Spring when the beetles are active (mating season!). The strengthening of a historic roof would usually take the form of inserting new timber alongside the original (not necessarily taking the original out). If the problem is more serious, you will need to seek the advice of an engineer experienced in dealing with historic structures. For major work, or sometimes even less major work (depending upon its precise nature) you will need listed building consent. I suggest that whatever solution is decided upon you speak with the Conservation Officer before any work actually takes place.

Period Property UK would like to thank Stephen Boniface Associates for answering this question. Stephen Boniface can be contacted on 01279 421 509

 
 
 
 

SUBJECT: Leaky Chimney Flashing
FROM: Robert Goodwin (Sandbach, Cheshire)
I have restored a Grade II listed farmhouse. Initially the builder used haunching round the chimney when mending the roof. This did not keep the roof dry and one of the beams and a large area of plaster was constantly damp/wet on the chimney column. The builder was encouraged (by non payment) to replace this with lead flashing. Several months later it is less damp but I believe some moisture is still getting through when it rains. Is there a way of inspecting the space beneath the roof tiles where the chimney column meets the roof without pulling down the old lath and plaster ceiling? Is this a service one can hire?

Robert Goodwin

This sounds a bit tricky and potentially litigious. If you have had the building restored you should not be getting a problem. Traditionally, roof to chimney junctions were finished with a mortar 'haunching'. Nowadays we tend to prefer lead flashings. However, if the mortar is properly finished (usually over a hidden metal soaker) there is no reason why they should not work well. Whatever, if you are experiencing a problem there must be somewhere the rain is getting in, even though you seem to now have lead flashings. It could be through the chimney itself, the flaunching around the pots, the pointing, a defective flashing joint, the roof tiles, the ridge. This requires careful investigation. I would not recommend taking down an original ceiling, unless as a last resort. Nevertheless, if there is a section of ceiling that could be used to form a loft access point, this might then be useful for access now and in the future. It might be sensible to have a small 'tower' scaffold erected or perhaps even hire a cherry-picker for a day. This would enable close inspection of the roof and chimney areas. Ideally you will need internal and external access to assess the precise cause of the ongoing problem. However, external access alone might be sufficient. If the cause is defective workmanship, you will need to have words with the builder - again! It seems that the best solution would be to find an independent local surveyor or architect (someone who understands old buildings) who can undertake the investigation properly and assist you, if necessary, in dealing with the builder.

Period Property UK would like to thank Stephen Boniface Associates for answering this question. Stephen Boniface can be contacted on 01279 421 509

 
 
 
 

SUBJECT: Flagstones May Still Require Some Elbow Grease to Clean
FROM: Steven Cenci (Chigwell, Essex)
We've recently moved into an old cottage with flagstone floors which are not original but laid some 20 years ago. The problem is those in the kitchen are quite dirty, I suspect from years of cleaning/wax products progressively trapping dirt. I've tried a little test patch with Flash and wire wool and this works reasonably well but would be a huge job to do all of it this way! Any suggestions for cleaning flagstones without damaging the finish?

Steven Cenci

Before tackling the problem you must try to establish what has been used in the past. If some form of sealant has been used it might be removable with appropriate chemical systems (used with great care). Some 'household' cleaning products might remove some forms of polish and/or wax. As you have already tried, you should experiment in discreet areas to see what works best. There are various removal chemicals available. One company specialising in removal of various finishes is Strippers. They have various franchise operatives over the country. Unfortunately, there is no guarantee that the most effective removal system will be easy!

Period Property UK would like to thank Stephen Boniface Associates for answering this question. Stephen Boniface can be contacted on 01279 421 509