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...

 

SUBJECT: Cut tie leads to movement in thatched cottage
FROM: Lucy Clayden (Cuckfeild, West Sussex)
We have a 15th Century, thatched cottage in Ashwell, Herts which we are painfully restoring. The cottage was originally 2 and has been amalgamated into one cottage. Upstairs 3 bedrooms were interconnecting which we are now putting in a new staircase and separating. One of the major structural beams going across the wall of the 3rd bedroom has previously been cut to make place for the doorway. There appears to be some movement in the beam & wall & we would like to make sure we strengthen adequately. My partner is suggesting we put a metal bracket around the beam and doorframe to ensure sufficient support. Can you recommend the best design for this and type of bracket we would need to get made?

Lucy Clayden

The structural beam you refer to was probably a major tie and whoever cut through it has weakened the integrity of the whole structure. However, you do not say when the work took place and the doorway formed. It is therefore difficult to advise whether this is a recent problem or something that has existed for many years. That said, you seem to believe there is movement between the beam and wall and if this is the case there is a problem that needs rectification. Your partner's suggestion is to try to connect the two sections of the beam around the doorframe is a sound idea but in practice the metal frame would need bracing to prevent it simply pulling apart and the work required is such that you would probably have to remove more of the beam and other fabric to be able to install the bracket. It is therefore unlikely that the suggestion is a practical option in this instance. Nevertheless, it would be advisable to seek advice from an engineer on such matters. The engineer should be experienced in dealing with historic buildings. One solution I have come across in the past is to use the floor to form a diaphragm structure that ties the whole building together and therefore the floor structure itself takes the place of the beam in terms of lateral restraint. Again without knowing the specific details of the property it is difficult to say whether this would be the most appropriate solution, but it is something you could consider.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: Seek independent advice
FROM: Maud Lemee (Edinburgh)
We have a flat in a Victorian Conversion. The property is a five story semi-detached property of traditional construction. The structure consists of load-bearing walls with timber floors and roof structure. The existing bressumer beam at second floor level is rotten at it's north end and, although there are no visible cracks in the parapet to indicate recent movement and the external wall is considered stable at present the replacement of the bressumer with steel beams has been commissioned by the managing agent. This is to strengthen the floor, front wall and roof. The existing timber bressumer would be replaced with two no. 178x102 UB's bolted together with channel spaces. The steel to be grade S275. There is an ongoing dispute as to whether the fact that the wall above the Bressumer has dropped slightly and moved forward at an unspecified time in the past has been a result of the rotting in the beam as described above, or is, in fact the result of extensive decay in the roof rafters which are also to be replaced. Our concern is that replacement of, rather than repairs to the Bressumer, is unnecessary and that replacement may cause more problems than it would solve.

Maud Lemee

Although you give useful detailed information, the problem you describe is one that would normally be best addressed following a site inspection. However, you mention that there is an ongoing dispute. I am therefore wary in providing too much information, as it is quite clear that the information provided could be used in a dispute. Without a site inspection and much more information it would be wholly inappropriate for this website to be used to support a point of view in a dispute, when the advice given is based on very limited information.

My recommendation is that you find a local professional experienced in dealing with older buildings to provide an independent report to you, which should be wholly unbiased. This can then be passed to the managing agents for their consideration. If it supports your view you can take it up with the managing agents and argue that the work being proposed is unnecessary and an inappropriate use of funds, etc. If the dispute proceeds further you may find that it has to be taken to the leasehold tribunal. However, you should consider that the opinion might not support your view.

With such significant work a managing agent would normally rely upon professional advice before embarking on structural repair. You do not say what advice the managing agent has obtained, if any. The purpose of obtaining an independent professional report is to either confirm the agents existing advice or to challenge it. Until you have an independent report from someone who has actually seen the problem and assessed it on site, it is not possible to provide any further useful guidance.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: Damp party walls in the actic
FROM: Mark Ford (Dorset)
I own a 3 floor early Victorian house in a terrace of 5. All of the houses suffer from recurrent damp on the party walls in their attic rooms. In my own case the stain has been there for at least 30 years. Sometimes it is wet and at others not - however the mark remains and grows very, very slowly. It seems to be associated with the wind/rain direction. Repairs to the flashings do not seem to help. We suspect that the large brick chimneys without [we think lead trays] are also responsible. My neighbours and I are considering trying to solve all the problems in one large job - even to the extent of rebuilding all the chimneys with appropriate leadwork. Everyone and his dog seem to have a view on what is needed so we would like to know where can we get sound expert advice on what is needed and what is possible?

Mark Ford

There are various possible causes for your present problem.

Plaster that is contaminated with salts will occasionally wet up and damp down as the hygroscopic salts absorb moisture. It could therefore be that your problem is partly or fully related to contaminated plaster. Plaster that is contaminated with salts will occasionally wet up and damp down as the hygroscopic salts absorb moisture. It could therefore be that your problem is partly or fully related to contaminated plaster.

You seem to have dealt with the problem of flashings but you should also check pointing, flaunchings and the pots generally. Disused pots should be capped with some form of ventilated cowling that will allow ventilation but prevent direct water penetration.

If you have covered all of these matters and are still experiencing a problem it will need to be investigated at close quarters by someone who properly understands older structures etc. At this stage I would be reluctant to suggest complete rebuilding. There are many Victorian houses across the country built without damp proof courses within the chimneys and they do not necessarily suffer the sort of problems you are describing.

You do not say whether advice given to date is based on inspection from ground level looking up to the chimney or whether scaffolding or other high level access has been provided for close inspection. It might be possible to hire a cherry picker or similar to gain close access and inspect in detail before making decisions on repairs or rebuilding.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 
 
 
 

SUBJECT: Sump pump makes more sense than tanking in damp cellar
FROM: Cathy Mayes (Cambridgeshire)
We have purchased a grade II listed building dated back to around 1840. It is a double fronted style house that sits directly on the village high street. The house has damp on virtually all internal and external downstairs walls. Whilst we accept that some of this is probably due to the front of the house being painted, the footpath being higher (or at the same level in places) than the ground floor, we also feel that the cellar must be playing a part, as it when we bought the property (in winter) this was filled with about 2/3ft of water. It has since dried out. We have had 2 people look at the problem. One says it is a small part of the overall problem and that a sump & pump should do the trick. Another has said that 'tanking' is our only solution at permanently dealing with it. The house, we have been advised, does not have a damp course. What would your view be about tanking V sump & pump? We are incidentally trying to get the footpath lowered or installing a French drain, and we intend to remove the paint from the front of the house. We will also replaster in breathable materials (lime etc), and intend to remove the concrete solid kitchen floor and replace with breathable. We will also sweep chimneys, remove secondary double glazing and unblock the air bricks. There was also approx. 1 metre high panelling in the front sitting rooms which we have had to remove as most was rotten with damp. The house is brick at the front and flint at the back. There has been virtually no maintenance carried out on the place in years.

Cathy Mayes

You seem to have most of the problems under control or at least in hand. Your main concern is whether to tank the cellar or not. It is my view that retrospective damp proofing of cellars is rarely 100% successful. A cellar is not intended to be a fully habitable room and on this basis alone I would opt for a sump and pump to deal with occasional flooding. The cellar can be used for storage or as a workroom (remembering that perishable items should not be stored in it). Where anything likely to rot is in contact with a damp surface there should be an isolating membrane. If you tank the cellar the moisture is likely to simply be driven elsewhere and could become more of a problem in other parts of the property. Undertaking all of the other work you identify should resolve your problems generally.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: Water seeps through our 3ft thick walls.
FROM: Mandi Randall Cramp (Essex)
We have a wasps nest in our thatched roof, how can we treat it without damaging the thatch? It is long straw thatch and the entrance to the nest is where the thatch meets the wall.

Mandi Randall Cramp

I do not believe that the fact the nest is in thatch need cause a particular problem. With many wasps nests a suitable poison is placed at the entrance to the nest so that wasps take it into the nest to spread the poison throughout the nest. The same principal applies here in that a suitable poison (probably in powder form) should be placed in and around the entrance to the nest so that wasps take it in and out and gradually poison the whole nest. When wasps have finished entering this area and it seems to be dead a thatcher should be employed to carefully undertake some localised repair of the thatch and close up the hole with a small section of new thatch. Depending upon the precise damage, it might be possible to insert what some thatchers call a bottle of thatch to close up the hole under the eaves.

With regard to dealing with the wasp's nest, I suggest you seek advice from a best control specialist in your district.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 
 
 
 

SUBJECT: Injected chemical DPC should be your last resort
FROM: Andrew Kershaw (Tyne and Wear)
We are in the process of purchasing a small stone built grade II listed house dating from c1901. It was built with a slate damp proof course, which my surveyor advises me it is on its 'last legs'. There are minor visible signs of damp in several ground floor rooms.

What is your recommend course of action in this situation (my surveyor has recommended an injected damp course), and how much should I budget?

Andrew Kershaw

I can only assume that your surveyor means that the edges of the slate are beginning to crumble and that the slate itself is showing signs of failure. This is something that can happen. It does not necessarily directly lead to a major rising damp problem and you indicate that there are only minor signs of damp within the property. In my opinion you should consider all other forms of damp and deal with them as necessary. You will find other answers on the agony uncle section of this site and many discussions on the issues of damp within the discussion forum section. Deal with the various forms of damp that might exist by general maintenance and normal building repairs, re-plaster and repair in an appropriate manner where necessary. This should deal with most if not all of the problems without the need for injection etc.

That said, where a property has a physical damp proof course that has clearly failed I am not wholly against providing a retrospective damp proof course in such situations. However, I would still regard it as a last resort.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: Should I sandblast stone floor to remove adhesive
FROM: Graham Sephton (Yorkshire)
recently uncovered an internal stone floor in the hallway of my listed Georgian property. Previously, the hallway had plastic tiles laid. In half of the hallway, the tiles had been laid straight onto the stone. The tiles have been removed, but the adhesive remains. We've been advised to dry blast the whole hall floor and then seal with a polyurethane sealant. Is this a good move ?

Graham Sephton

I would not recommend sealing the tiles. I have not personally tried to dry blast remaining adhesive from tiles. It would be sensible to speak to manufacturers of tile adhesive to find out if there are solvents that will remove adhesive remnants.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: Lime ash floors should be as reliable as modern flooring materials
FROM: Richard Porter (Leicestershire)
I'm in the process of buying a cottage in Leicester. I am not sure of the age of the property but most in the area have thatched roofs. My main concerned relates to the material used for the upstairs flooring which appears to a mixture of plaster and hair. Would this be the original floor? I am concerned about its strength because it's damaged - could I replace it with a more modern flooring?

Richard Porter

What you describe may be a lime ash floor. These are relatively uncommon and an important feature. They are quite strong and if looked after can serve very well for many years. The SPAB have produced a leaflet on the repair of lime ash floors and there is an increasing body of knowledge relating to such floor structures.

You do not say whether the building is listed, but if it is then you will not be able to replace the floor without consent, which I doubt would be given. I suggest you look into methods of repairing the floor. There is no reason to suspect that a properly repaired lime ash floor should be any less reliable etc than a more conventional floor.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: So-called damp experts offer confused advice
FROM: Alistair Saddington (Surrey)
I have recently purchased an 1830s terraced house. The survey highlighted some damp in the utility room on an east-facing retaining wall (bubbling plaster and rotting skirting board to about 6in above floor level, which is about 2ft below ground level). The situation is complicated by the proximity of an external door and soak-away? from the guttering. I cannot excavate the earth bank, as I don't own the land behind the house. I have had three so-called 'damp proofing specialists' to investigate with three different solutions: 1. rising damp? (full dpc), 2. penetrating damp? (tanking) 3. Don't know mate but it's not rising damp. I have no confidence in their 'moisture meter waving' 5 min solution diagnostic techniques. I am at a loss as to what to do next. Can you recommend a company who will carry out a proper investigation of the problem?

Alistair Saddington

If the wall in question is below ground level it is likely that dampness is penetrating through the wall. A horizontally injected or a physical damp proof course will only stop rising damp from below the wall but not laterally through it. Tanking will of course help prevent lateral water penetration but does not last forever and is not 100% satisfactory.

If you cannot excavate the earth bank you have to accept that there will be an amount of water penetration through the wall. There are many other replies on the agony uncle section of this site with regard to possible solutions for similar problems and there are many discussion forum threads on similar subjects. A system I would probably want to look at in your situation is a drained cavity system using one of the proprietary membranes such as newtonlath, delta or platon.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: Cottage built into hill causes damp problems
FROM: Adrian Andreou (Greater Manchester)
We are currently in the process of renovating an old cc1831 stone cottage, built at the base of a hill. It has a serious damp problem, and has had concrete and ashfelt floors put in, in the past, and cement and sand mix on the walls upto a metre. note it also has higher ground levels externally, the higher the ground, the worse the rooms affected. My architect has suggested breaking up the ashfelt floors and inserting concrete ones throughout, and lowering the ground levels externally with the aid of a drain system around the house. I am particularly worried about putting yet more concrete as I have read from articles that is detrimental, however, I am having difficulty finding out exactly what way I could do it otherwise. For instance if I wanted to install stone flooring throughout, no company will lay them on anything other than a damp- proof membrane. I would like some advise as to what kind of materials and layers would provide a breathable, yet suitable, surface for the laying of a stone floor, and advice about individuals that can lay such a floor.

Adrian Andreou

Your architect's suggestion of creating a drain around the building sounds very sensible as this helps to divert some of the ground water from the building and reduces the amount of moisture that can directly enter the building. This should be undertaken in conjunction with lowering ground levels.

As for other works it will depend on circumstances but my preference would be for allowing the walls to breathe naturally. There are other answers within the agony uncle section and discussion threads in the discussion forum regarding similar problems. Within the discussion forum you will also find threads on how to lay floors that are breathable.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: Modern wonder-solutions which seal external walls may aggravate damp & spalling problem
FROM: Ryan Gearing (East Sussex)
I recently had a survey by Coatex who you may have heard of and they pointed out some drying pointing and spalling brickwork to me. I didn't want to pay their price for the remedial work so would welcome your suggestions to cope with the work and prevent any further decay. My house is mid terrace, age somewhere between 1893-1900.

Ryan Gearing

I would always advise great caution with regard to these modern systems that aim to seal the walls and provide long lasting protection. Quite often they simply aggravate the problem when applied to older buildings.

You may have some defective pointing that needs to be attended to and if the house has been re-pointed with a dense cement mortar it could be that the spalling and deterioration is related to this. As a rule of thumb pointing should be the sacrificial element of any elevation and should generally be softer than the surrounding brickwork. If this is not the case the brickwork will suffer first and deteriorate more rapidly than the pointing. In your instance you may find it necessary to rake out and re-point in lime mortar. With regard to spalling brickwork I generally leave brickwork alone unless the deterioration has become so bad that it could affect the integrity of the wall structure in terms of allowing water to penetrate through, etc. If spalling is so bad that bricks have to be replaced then suitable matching bricks should be used and the damaged bricks carefully cut out and individually replaced. I would not recommend trying to cover spalling brickwork in any way with render, etc.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: Roof insulation advice sought
FROM: John Astleford (Lincolnshire)
I have an 18th century barn (grade 11) on my property. The previous owner retiled the roof on top of a pitch lining. I now want to insulate between the joists and still leave part of the joists exposed. Is this possible or do I have to leave a 50 mm gap between the lining and any insulation. The joists are about 80mm thick. I intend to use the barn as a playroom for the kids and a computer room. On final question, the joists are pine but are supported by oak beams. What coating would best suit the oak and pine for preservation and looks.

John Astleford

As the barn is listed the work you describe will require listed building consent. Further if you wish to use the barn as a playroom and as a computer room it may require consent for the change of use. You should therefore seek proper professional advice and may require drawings for the work.

As a general rule, if you were to insulate between the rafters it would be necessary to leave a ventilating gap above. As the present lining on the roof is impermeable even a ventilating gap above the insulation may be insufficient and there could be problems in the medium to long term. I would perhaps favour cutting away the lining altogether. The insulation could then be installed and there would be natural ventilation through the tiling. Nonetheless, advice from a professional with experience of this type of building in your district would be sensible. I recently met some building control officers from Lincolnshire region and found them to be very approachable and reasonable when it comes to dealing with listed buildings. You may therefore be fortunate in finding that the building control officers would have some helpful suggestions.

With regard to the coating, I would prefer to leave the timbers without any coating at all or simply use something like bee's wax.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.

 

 
 
 
 

SUBJECT: External drainage system required to deal with damp
FROM: Graham Boycott (Lincolnshire)
We live in a 3 storey weaver's cottage. The back wall of the ground floor is into the ground. The floor seems to have the original stone slabs covered in bitumen. We want to reclaim the floor back to its original stone. However there seems to be a problem with damp on the back wall and also through the floor. We have had one suggestion that is to lay drainage ducts from the back wall under the new floor (which we would like to be heated) to the drain at the front of the house. Does this seem to be a reasonable way of attacking this damp or is there another way? Also the stone is quite weathered what means are available for protecting it.

Graham Boycott

You do not say whether the high ground level at the rear is land belonging to you or not. If so you should look at either lowering the ground level or putting some form of external drainage system in to take water around the building and away from the wall.

Without seeing the precise situation it is difficult to know whether the suggestion provided would make sense. I have not necessarily seen draining through under a floor but on the face of it there is not reason why this should not work. That said, I would prefer to lay some form of land drainage around the building externally rather than take it under the floor.

There are a number of ways of dealing with the walls and floors if they remain damp and this would include a drained cavity system of some description.

You will note my earlier answer about floors and within the discussion forum you will find other threads looking not only at the question of forming breathable floors but also incorporating heating systems.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at the The Whitworth Co-Partnership with Boniface Associates for responding to this question.