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 Khaki stains on lime plaster Jacqueline Martin-Greatjead (Lancashire)
o Large chunks of myhouse are falling off Hedley Francis (Cambridgeshire)
o Building a flint wall for outbuilding Antony Etwell (Surrey)
o Do open fireplaces provide background ventilation Peter Smith (Greater London)
o Inglenook restoration in need of structural advice Frances Tanner (Somerset)
o Rules of thumb for underpinning quotes Dawn Brealey (Lincolnshire)
o Borehole water staining - is this normal? Tony Aucott (Powys)
o Fumes leaking from flue into attic bedroom Cath Holmes (Lancashire)
o Penetrating damp Sarah Wickham (Yorkshire)
 

SUBJECT: Getting rid of khaki stains on lime plaster
FROM: Jacqueline & Gerald Martin-Greatjead (Burnley. Lancashire)
We own a 17th century farmhouse which we have restored to its former glory, including replacing any cement plaster with lime plaster. We have painted throughout with pigmented (suitable for the purpose) limewash. In one of the rooms in particular significant areas have developed khaki coloured stains showing through the paint and looking unsightly. We have attempted to repaint these areas but the stains return. Do you know what might be causing this and/or what we might do to get rid of the problem (the areas effected are a combination of new and old lime plaster?)

Jacqueline & Gerald Martin-Greatjead

It is difficult to be precise without looking at it, but if the stains are on a chimney breast, or near a flue, then they might be tar stains coming through from the chimney, which is a common problem. Alternatively it might be that the old plaster was damp, either immediately before you painted, or at some time in the past. Which ever the cause, re-limewashing will only make the staining worse, and you will either have to replaster, or seal the stained areas and re-colourwash over the top. Very few people limewash the insides of their homes these days, so you must be pretty keen!. Good ventilation will also be important to keep the limewash fresh.

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: Large chunks of my house are falling off
FROM: Hedley Francis (Cambridgeshire)
We have a timber-framed house which requires a long exposed (exterior) wall to be re-lath and plastered. Large chunks just fell off - it appears the previous maintainers, probably around 15 years ago, replaced the outer skin. They appear to have kept some areas of old lath, re-lathed other areas and then draped expanded metal mesh over the whole wall before plastering the exterior, probably expecting the plaster to key onto the laths. It didn't, and the mesh is only attached occasionally with the odd nail. The nails have rusted through, as has the mesh, which has in large sheets separated from the laths.

This is not the problem (we can handle this), but is an interesting cautionary tale not to mix mesh with laths unless you really secure the mesh well. Oh, and if you must use mesh for some reason then use stainless mesh and nails.

However, this wall is next to a drain/ditch with a concrete path at the bottom. This is below the level of the cill/sole plate and the part of the wall below the sole plate is leaving outwards (say maybe 5-10 degrees).

Examination below the crack (with a chisel) shows that the part below the sole plate is a brick wall (around 3, maybe 4 courses high from the concrete path) and that the house & plate do not in fact sit on this wall.

All that sits on the wall is a cement render which gets thicker towards the bottom of the timber frame, until it is the width of the brick wall.

I don't yet know for sure what is below the house frame, but I assume that it sits on the modern concrete (with DPC) floor, and that behind the brick wall is earth (clay).

I assume that the weight of the house is squeezing the soil below which is pushing the wall outwards - although it might just be the weight of the plaster on top of it.

So the question is: do I need to do anything about this, and if so what is the minimum?

Would rebuilding the wall, with about a foot of concrete behind it (extending under the floor and sole plate) and some underneath it (acting as a minor foundation) be enough to stop the soil being squeezed out?

Another alternative would be to half fill the ditch with concrete (the ditch starts at one end of the house, so nothing drains into it from that end - but of course plastic pipes could be laid even if it did). Would the wall have to be rebuilt before doing this?

In both cases would the weight of concrete cause a problem in compacting the earth further?

Hedley Francis

Without knowing precisely how the structure has been formed and how it is working it would be impossible to give definitive advice. From what you describe I suspect that if there is not a present or ongoing problem then there is certainly a potential problem for the future. I therefore advise a careful programme of investigation in the first instance. You should very carefully remove a few bricks externally to see what is behind them. Ideally this should be in an area that will also reveal the relationship between the brickwork, the sole plate and internal concrete. Internally you could carefully remove finishes (assuming they are not historic) at the base of the wall to find out how the timber frame sits on the wall and/or concrete slab. If the wall is leaning it is probably due to lateral and/or vertical loads and/or a sub-soil problem. The minimum you need to do is to investigate precisely how the various elements relate and therefore establish what might be causing the defect. If the wall in question is bearing no load and is merely a 'decorative finish' the fact that it leans may not matter. If it only has the render onto it, re-rendering in a way that does not rely on this wall for support would remove the probable cause and reduce the need to do anything to the wall itself. If, however, the wall bears main loads, it might need re-building with a new foundation. With the information to hand I cannot give more specific advice, but I hope that this gets you started in the right direction.

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: Building a flint wall for outbuilding
FROM: Antony Etwell (Surrey)
Can you advise me on building a flint wall for a new outbuilding? The intended structure is to be a rubble knapped flint construction with red brick cornering.

I'm looking for advice on how to lay the brick and flint i.e. do I lay 3 courses at a time? how should I mix the mortar and where's the best place to obtain the correct flints?

Antony Etwell

I can do no better than refer you to someone who provides training in such work. You will need to get some advice and/or training from someone who is a specialist in such work. I therefore advise you to look at the following web site and consider either going on one of the courses mentioned or at least paying for some individual tuition. www.flintman.co.uk. The Society for the Protection of Ancient Buildings have a good technical pamphlet on the subject. Tel 0207 377 1644, or look them up on their web site.

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: Do open fireplaces provide background ventilation
FROM: Peter Smith (Greater London)

I am refurbishing a Victorian terrace house in London. Building control have asked for background ventilation to be provided to all habitable rooms. I don't want to use trickle vents in the windows, and I don't want to put airbricks in the external walls. All the rooms have open fireplaces. Do these not provide the background ventilation the regulations require?I am refurbishing a Victorian terrace house in London. Building control have asked for background ventilation to be provided to all habitable rooms. I don't want to use trickle vents in the windows, and I don't want to put airbricks in the external walls. All the rooms have open fireplaces. Do these not provide the background ventilation the regulations require?

Peter Smith

I would have thought that using a flue would satisfy the requirements. It is after all a chimney and will draw air through it, thus giving the ventilation required. Unless you have hermetically sealed every gap to all external walls, roof, floor, etc there will always be some air leakage that will allow air into the building anyway. You should remember that the regulations require adequate ventilation, but there is nothing in the regulations that tell you how this must be done. The Approved Documents are not the regulations themselves and only set out a possible method. It is my view that using the flues would meet the regulations and I have seen this method in many buildings - indeed I recommend it as a method of ventilating rooms.

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: Inglenook restoration in need of structural advice
FROM: Frances Tanner (Nr. Somerton, Somerset)
I am trying to restore an Inglenook fireplace in our 16c cottage. Our builders are reluctant to expose the fireplace as they are concerned about the lack of support behind the modern fireplace which was installed about 50 years ago. The very large bressumer beam has been removed sometime in the past but a very large supporting stone is still in place, at least on the one side. A small pilot hole has revealed there is rubble within the space. Can you please suggest who we may contact in the Somerset area to get some professional structural inglenook advice.

Frances Tanner

If the building is listed, have you got consent for this work? Assuming that you have consent or that it is not required I would urge caution. A chimney, especially one forming an inglenook, contains a large number of bricks and collapse of this would be a major disaster. It should be possible to carefully remove the front of the modern fireplace and hack off plaster around the area. This should reveal the construction above and around the opening you wish to create. It should be possible to source a suitable piece of timber to form a new bressumer and insert this. I would prefer to insert the bressumer before removing the other brickwork below to then cut through to the original fireplace behind. If this is not possible you should aim to install a temporary beam. From your description I am not sure what the 'supporting stone' is doing and if it is only on one side it may be best to ignore this and not rely upon it. What you should be looking to achieve is a satisfactory permanent horizontal support for the brickwork above before removing the whole fireplace and clearing the void behind. For a specialist on inglenook fireplaces I would refer you to the following web site. www.inglenookrestorations.co.uk

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: Rules of thumb for underpinning quotes
FROM: Dawn Brealey (Cheshire)
A property I am thinking of buying requires underpinning, i am looking at getting a quote for the work but is there a rule of thumb that might help to tell if the quote is fair, some American sites have quoted so much per square yard, I am after a very rough guide to see if the property is worth it without spending too much initially.

Dawn Brealey

Who says it needs underpinning? If it does, why hasn't the owner submitted an insurance claim that you can then take over (you have to pay full market price ignoring the defect and the insurance company pay for the works) - this is called transferring a claim and is not uncommon. If it is not insured, why not? If the building is a dilapidated property that is not inhabited and not insured then I accept that the price you pay has to allow for any and all repairs, which might include underpinning. If an engineer has recommended underpinning find out on what information, evidence, investigation data is this advice based. Does the engineer understand and have a sympathetic approach to older buildings (those who don't may recommend works that are not necessary)? Unless the problem has been fully investigated do not simply accept that underpinning is needed. I generally regard underpinning as a last resort. From a negotiating viewpoint underpinning could push the costs of repairs upwards considerably and this could aid your negotiation in getting the price lowered. This is a different matter to the simple question of whether the property requires underpinning.

The cost of underpinning will depend upon several factors. Underpinning can mean excavating under the existing building and filling these excavations with concrete; it could mean piling. The depth of underpinning required will affect the cost. The ease of work will be an important factor - with some properties the work has to be undertaken from the interior only, making the work very difficult. What other works may be involved? For example, underpinning can often affect drainage or at least gullies. Will the repairs have to include repair to the superstructure above ground?

To give some guidance, in London, conventional underpinning to a depth of 1.5m with some drainage works to a wall c.3m long is likely to cost c10,000 (up to 15,000). For a standard Victorian/Edwardian terrace house in London I would use a budget figure of at least 10,000 for each wall length.

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: Borehole water staining - is this normal?.
FROM: Tony Aucott (Powys)
We're thinking of buying a 200-yr. old cottage where the water supply is via a borehole. We have noticed the bath is stained brown and the Vendor says this is a reaction to the borehole water. Is this staining quite normal or is it a problem with the water quality? Also, should we have the borehole tested for drinking water quality

Tony Aucott

Some water with high mineral content can cause staining. However, the local Water Authority should be asked to test the drinking water. It is a requirement for non-mains drinking water supplies to be regularly tested anyway and the owner should be able to provide paperwork from the last test. If not, or if the test is old, have the water tested before committing to the purchase. If the supply is contaminated the Water Authority will usually investigate the source and deal with the problem whilst putting you on a temporary supply. It is in their interest to ensure good quality water, as their own local supplies could be from the same basic source as yours.

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: Fumes leaking from flue into attic bedroom
FROM: Cath Holmes (Accrington, Lancashire)
We have recently purchased a house parts of which are 400 years old. The ground level in this part of the house is lower than the outside ground level. The inside of the walls have been treated with vertical structural waterproofing by the previous owner. On the instructions of our surveyor we had the render taken up by three courses as it was at ground level outside. On doing this we discovered a retaining garden wall 12 cms from the house 41 cms deep with concrete underpinning at the bottom. This trench was filled with soil and as a result the bricks of the house were sodden. We have cleared out the trench along the side of the house to allow the bricks to dry out. Please could you advise the best way to fill this trench to allow drainage and stop the wall absorbing too much moisture.

Cath Holmes

If the neighbour is experiencing smoke whenever you light a fire there is a leak between your flue and next door, regardless of the results of the tests and the fact that you have no problem within your property. It may be that your flue is working well, but it could still leak to next door. If you use the fire and cause problems of smoke next door they could probably get an injunction to get you to stop. I doubt if the dry lining is the problem, because a chimney flue should not leak regardless of the finishes to walls. I suggest you liaise with the neighbouring owner to share the costs of full and thorough testing of all flues to get to the heart of the problem. If it is found that works undertaken next door (the joists in the chimney) are the cause of the problem you could legitimately request the neighbour to sort it out at his/her own cost. If the neighbour refuses you would have to take legal action. If you need to take legal action have you checked your insurance policies to see if you have legal costs cover? If so, put the matter in the hands of the insurer's solicitors. If the neighbour will not liaise at all you have few choices. If you can prove that the problem is next door you could light up and wait for them to take action against you, at which time you defend it and put forward the evidence you have that the problem is of their own making. This is a very risky tactic and not one I would recommend. From a purely pragmatic view, it will be quicker and could be less costly in the long term to simply have your flue lined. At least this way you will know that your flue cannot be leaking at all. As for legal responsibility, you would need to seek the advice of a solicitor, but you would need to put all your evidence together and demonstrate that you have taken all steps possible and that the solution to the problem is very much in the hands of the neighbours. If the neighbours will not do anything your only recourse is to take legal advice/action.

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: Penetrating damp
FROM: Sarah Wickham (Huddersfield, Yorkshire)
We have a late Victorian detached house, with a cellar which has penetrating damp (the floor is approx. 1.5 metres below ground level). The walls have been rendered on the inside with thick, impervious cement-looking render which we are planning to remove as it seems to be trapping moisture in the walls. We also have a sump, and the window is kept locked open for ventilation. There is also a radiator in the largest room which we keep on during the winter.

The previous owner kept a chest freezer in one of the cellar rooms, and the flags (which appear to have been laid direct on the earth) are lower where the freezer was. When it has been raining there is a lake up to 5cm deep in this area. So should we try to lift and relay the flags here, putting sand or something underneath just to raise them up? Or should we just live with the lake - it vanishes after a few days of dryness.

Sarah Wickham

Is there an obvious reason for the lower floor? Is it original or clearly a later alteration?

If not original and there is no practical reason to keep the lowered area I would probably consider reinstating the floor to a level that matches the rest of the floor (using traditional materials/methods). This may solve the problem. However, if the water disappears after a few days it is obviously draining away and is only a temporary problem during periods of rain. The main question is what materials are in the area that could be damaged by water? If there are timbers within the area that gets wet they could rot, in which case you should take some action to resolve the problem. There are other answers in Agony Uncle and postings on the Discussion Forum on such problems that should help you to a solution.

In the alternative, if there are no timbers likely to suffer I would be tempted to say "why worry?". The joists to the floor above are perhaps vulnerable in a general way, but unless the water is in contact with the timbers it will not directly cause rot, particularly if the cellar is well ventilated. If there are a few timbers in contact with walls that are periodically wet the individual timbers could be protected by isolating membranes between the timber and wall. The other question is whether any timbers are deteriorating at present? If so, repairs will be necessary at which time localised treatment and isolating membranes might be appropriate. If there is no apparent problem, I would suggest that the water ingress is not too much of an immediate problem. In any event, I would be hesitant to suggest a tanking or dry lining or drained cavity system in a cellar that is merely used for storage, occasional use, etc. I would only consider major intervention if you intend creating a fully habitable room.

In conclusion, the question you really have to ask is what damage is it really causing? Cellars are usually damp places and do occasionally get wet. Unless or until this causes damage to the fabric of the building I would be hesitant to recommend too much work.

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.