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).

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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...

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SUBJECT:
Aggessive acid on brickwork
FROM:
Andrew Hunt
(Greater London)

We recently moved into a late Victorian house that has had some form of acid wash applied to the exterior brickwork. While the brickwork is now a lovely yellow colour, the acid seems to have been too aggressive and has stripped some of the facings of the brickwork, leaving it looking rough and pockmarked in places. I see from a previous question that you have not recommended sealing of this brickwork, but would the same thing be true in our circumstance, where the facing of the bricks have been damaged?

Andrew Hunt

Although modern bricks tend to be fired at a fairly consistent temperature so that the internal areas of the brick are almost if not as hard as the skin with some historic brickwork this was not always the case. Some historic brickwork could be regarded much like a loaf of bread with the hard outer crust and a softer inner core. If the outer fired face is removed it exposes the core and this is more likely to deteriorate quickly through weathering etc.

I suspect that the bricks you refer to are London Stock bricks. The acid has probably been left on too long or not neutralised quickly enough after use and the acid has continued to cause damage to the brick faces. It is quite possible that the softer core has now been exposed and this may over time lead to some degradation of the brickwork.

However, I am not convinced that sealing the bricks is the solution. Apart from the whole issue of breathability there is the practicality of having to re-seal the bricks on a regular basis. When a surface is pitted and uneven any sealant will not cover the brickwork 100%. There will always be some gaps and this could lead to problems in future. The sealant itself deteriorates after a few years and has to be reapplied sometimes every 3 - 5 years although quite often at longer periods. For these reasons I am generally against sealing brickwork.

I suggest that you look to neutralise the acid even now as it might stop any further degradation.

Only time will tell whether there is any long term damage. At present I would tend to leave the wall alone. If you find that water ingress does occur due to the softer core being exposed and allowing more direct water penetration you might then have to consider some form of finish applied to the surface. This could be a lime wash (coloured if necessary), a lime render or you might consider a sealant but as indicated above there are drawbacks.

Whatever form of sealant or finish is used it will not remove the rough appearance.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at The Whitworth Co-Partnership for responding to this question.
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SUBJECT:
Neighbour's planter causing damp
FROM:
Gareth Peace
(Northumberland)

I have a barn conversion with a detached stone building that I use as a garage/store. One side forms part of the boundary with my neighbour. He, against my wishes, has constructed a planter against that wall, seemingly without taking steps to isolate my wall from the soil. Inevitably this has made the environment damper inside to the detriment of my tools and equipment. Of course, it would be best to resolve it amicably, but the background to this and my experience in dealing with him suggests that I should at least be prepared for some difficult negotiations. Any advice on how I stand in law would be appreciated.

Gareth Peace

A website you may find very useful in your situation is www.boundary-problems.co.uk

As a general rule of law no-one should do anything along a boundary that causes damage to the neighbouring property.

Of course without access to the neighbouring site it is difficult to know for certain whether the work undertaken has or will cause damage to the boundary wall and/or to your side of the boundary. However, if necessary you could get a building surveyor to inspect and check the condition of your wall and perhaps, with your neighbour's consent, for that surveyor to look at the other side and to advise whether or not there is a potential problem etc. and how best it could be resolved.

I should mention that if your neighbour has provided adequate protection against the wall or fence and installed a planter so that the installation of the planter does not cause a problem then your position may be weak. That said it depends on who is responsible for maintaining the fence or wall. If it is effectively your wall then your neighbour has no right to fix to it in any way. If it is his wall he has the right to fix to it but not in such a way that causes damage on your side.

The above comments are rather general and should not be taken as completely applicable in your specific situation. You should seek legal advice and seek advice from a building surveyor who can undertake an inspection. With regard to legal advice you might want to consult your household insurances etc. in case you have cover for legal costs.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at The Whitworth Co-Partnership for responding to this question.
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SUBJECT:
Cleaning red brick
FROM:
Simon Dudley
(Lancashire)

Is there a way I can clean up the face of the bricks on my house. They have become black and stained over the years and I would like to find a way to do this myself if possible. The house is circa 100 years old and built from a hard faced red brick. The house is also being re-pointed, so if the cleaning process damaged the pointing a little, that would not be a real problem.

Simon Dudley

Cleaning any building is often contentious. In some instances the accumulation of dirt and pollutants on the face of a building can actually cause damage and it is therefore beneficial to gently remove those materials. However, there are instances where more harm can be caused by cleaning a building than by leaving it alone. By cleaning you can remove the 'patina of age' and fundamentally change its appearance as now known by all who see it regularly.

Setting aside the philosophical arguments about whether to clean or not there are a number of methods for cleaning. Which method is used will depend upon what is causing the dirt etc. You may find that simply gently brushing the surface will remove dirt that has accumulated and that this might be sufficient for your purposes. You could find that carefully washing down the surface is sufficient. However, you may find that a more aggressive form of removal is necessary or perhaps even chemical removal. There are a number of possibilities and it would be inappropriate for me to try to advise on the most appropriate in your specific situation.

You should seek advice from specialist cleaning companies in your region (speak to a local Conservation Officer if necessary about companies that have cleaned major buildings successfully). You should find a relatively hidden part of the building and try various different methods if necessary to establish which would be most appropriate and least damaging.

The use of coarse aggregates for blasting the surface is generally not accepted because of the damage it causes to the surfaces of the bricks. However, there are other methods including a form of steam cleaning and other methods that are slightly abrasive but not such that would necessarily cause damage to the brick faces if carefully used. It is important that you seek specialist advice and have trial areas undertaken as indicated above.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at The Whitworth Co-Partnership for responding to this question.
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SUBJECT:
Damp brickwork generating brick dust
FROM:
Judy Hirst
(Cambridgeshire)

We have a 17th century timber frame cottage, in which the timber frame rests on a brick base. In the living room, containing an original brick fireplace in the wall which joins our cottage to next door, the floor is below ground level, and the old brickwork (around the bottom of the walls and for the lower layers of the fireplace) is damp (up to 20% reading on meter). A few (perhaps 5%) of the old bricks are beginning to crumble, generating a slow but steady supply of brick dust into the living room, and I would like to consolidate the surface to prevent this. I am wary about applying a silicone brick sealant, as I do not want to trap water inside the bricks and make the problem worse. Could you suggest the best course of action? In the fireplace the pointing is lime mortar, but around the room this is not the case.

Judy Hirst

Lower the ground level externally and allow the brick plinth to breathe so that moisture can escape readily from both sides before it reaches the timber frame.

I would not recommend applying a sealant to the brick surfaces as it would indeed trap moisture on the inside and could cause other problems as you suggest in your question.

Without inspecting it is difficult to be too specific but in general terms I would try to ensure that the plinth wall is exposed both sides and with breathable finishes etc. so that the moisture can evaporate freely. Where brickwork is beginning to deteriorate one needs to establish why this may be happening and it could simply be because the other side is not exposed and if it were to be exposed the brickwork might be relieved of some of the moisture and this would help prevent the problem worsening.

It is possible you may have to consider rendering the surfaces with a lime render. This may have to be sacrificial initially because after a few years it may fail whilst the wall is still drying out and the brickwork still reaching a point of stabilisation.

You mention that the fireplace has lime mortar but indicate that the rest of the room does not. Again without knowing more detail about this I cannot be specific but I would suggest that the plinth walls need to be formed traditionally in lime mortar with lime pointing etc.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at The Whitworth Co-Partnership for responding to this question.
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SUBJECT:
The floor has damp patches and effloresces in places
FROM:
Mary Lou Downie
(Northumberland)

We have a 200 year old farmhouse, which we use at weekends and will move to full-time in a couple of years. It has 2ft thick random rubble sandstone walls and a 1930s- 50s concrete floor without damp proof membrane. The floor has damp patches and effloresces in places. To prevent penetrating damp & draughts we have had a lightweight blockwork inner leaf built, with insulation in the cavity - bliss! It rests on concrete foundations for which a strip of the concrete floor around the walls was removed and has its own damp proof membrane. Having sorted out the walls, we're left with the damp floor - which is grubby and we want to cover it with something more friendly. I see lots of epoxy resin sealers advertised and also cementitious tanking systems, on either of which we could lay an engineered wood floor...but would this be effective or risking trouble?

Mary Lou Downie

Without drawings and photographs I can only guess at what you have already undertaken but it seems to me you have created an independent inner wall and therefore the original sandstone walls are isolated to a large extent from the inner concrete floor. You have effectively created a modern structure within the older structure. If this is the case then there are questions that arise about how the original sandstone walls will now function and whether there is sufficient ventilation to both sides to allow them to dry out fully or whether they will simply become damp over time. Nonetheless your question is about the floor. If you have created a modern wall with damp proofing then to create a damp proofed concrete floor is unlikely to worsen the situation as far as the original building is concerned. A concrete slab, whether it has a damp proof membrane or not, will restrict quite a lot of moisture and therefore the building has been working without a breathable floor for many years.

You have a choice of either taking up the existing floor and recreating it or to create a new floor on top of the existing. There are a number of surface applied damp proofing systems that can be used over the floor and up the walls. The important thing is to ensure that any damp proofing in the building is continuous and therefore any damp proofing to the floor needs to lap into or link to the damp proofing in the blockwork walls you have had built.

The issue of the breathability of the floor is something that would need to be considered only following a site inspection. If breathability is particularly important in this instance you could consider laying a modern limecrete floor. You will find various threads in a discussion forum section of this site relating to limecrete floors.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at The Whitworth Co-Partnership for responding to this question.
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SUBJECT:
Woodworm noted in surveys
FROM:
MC Card
(London)

I am in the process of buying a house for the first time. I did a homebuyers report. Overall the report was satisfactory. However the surveyor noted the existence of inactive woodworm infestation to the surface of the timber floors. I checked with the current owners and they tell me that the house was treated at the time they bought it (4 years ago). I received a letter from their solicitor confirming this, however there are no guarantees since it was done by the previous owners themselves. They lifted the floorboards and treated both sides of them and also the floor joists.

I subsequently arranged for a survey which reported the evidence of woodworm (but no mention if active or inactive) and suggested treatment (about 500). The evidence was only found in the living room and hallway but not in the roofing timbers. However, the survey was free and the company provides the treatment themselves, so I am a bit suspicious. The survey was done very quickly and floorboards were not lifted. Should I contract another company to check the property?

MC Card

What is often forgotten when looking at timber infestation is that once beetle infestation has created a flight hole the flight hole is there for evermore. The presence of flight holes does not necessarily mean an active infestation problem.

You do not mention the age of the house or the nature of the timber and I therefore assume that we are talking about common furniture beetle rather than death-watch beetle or other form of infestation. Surface treatment of timbers is reasonably effective for common furniture beetle if indeed it is active. However, treatment of timber where there is no activity is simply a waste of money.

The lack of a guarantee is not in my mind a particular issue because many guarantees could be regarded as fairly worthless anyway. The important thing is whether there is any activity. It is quite likely that if the previous owners did the work themselves they were actually quite thorough and may have done as good a job as any specialist company.

It is possible to have timbers checked to establish whether they contain any treatment fluid and you might want to have this undertaken. This will give some indication of how thoroughly the treatment was carried out.

The reality is the property probably has very little if any active infestation with the flight holes probably being historic. I would doubt whether extensive further treatment is necessary. I would therefore be hesitant about paying for yet further treatment. However, it is important to establish whether there is any active infestation. It could be useful to ask the original surveyor and the specialist company to point out to you where they found active infestation and not merely historic flight holes. If they cannot identify active problems I would suggest that you save your money on the treatment. However, be aware that if there is some activity you encounter at some future date in the property you may have to undertake some limited targeted treatment at that time (not dissimilar to what the previous owners did).

Bearing in mind that you are aiming to purchase the property and this all takes time you may take a commercial view that it would be easier to simply try to negotiate with the vendor to pay perhaps 50% of the suggested cost of treatment and at least that way you have some contribution should you find that treatment becomes necessary at some future date.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at The Whitworth Co-Partnership for responding to this question.
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SUBJECT:
Stains applied to oak beams
FROM:
Cherrie Cray
(Suffolk)

We are renovating our Tudor farmhouse which over the years has had various stains and varnishes applied to the oak beams. We were advised to use a product called Kling Strip which left the beams brittle and covered in a brown film (which when wet felt like oil and when dry looked like a brown resin). When we contacted the manufacturers they sent out a contractor who said that all the stain etc had been removed and he believed the product to have "overworked" pulling some of the natural oils from the beams. He advised applying raw linseed oil to replenish the wood assuring me that the product would not darken the beams. Having applied the linseed oil (and having substantially darkened the beams to a point that they now look exactly the same colour as they did when we started the process) I am at a complete loss as to what to do now. I have since read that it is virtually impossible to undo the "damage" that the linseed oil has done. To make matters worse we have! 1/2 of the beams in the room looking perfect (they were hidden behind a lathe and plaster wall/ceiling) and we want the beams that have been linseeded to match (as close as possible) the untouched beams. So far I have been keen not to sandblast the beams but I am struggling to find an alternative having spent three weekends wrecking our beams with paint stripper and oil.

Cherrie Cray

Whilst there are a number of products available to help remove stains, varnishes and paints to beams and the public can readily buy these and use them the actual application and use of these is quite a specialist task. It is often necessary to experiment in small discreet areas to find out just how long to leave the material in place to optimise its impact. It is also important to remember to neutralise the effect of the chemical as soon as you remove it so that it does not continue to act on any material in the timber. Leaving it on too long and failure to neutralise are perhaps the most common problems found.

It is quite likely that if the material was left in place for too long it would have pulled out some of the natural oil etc. from the timber. To replenish the oil applying linseed oil is what would normally be recommended. However, once again it is best to deal with this in small areas to see what impact it has. In this instance it seems that it did cause further darkening of the beams. Unfortunately there is very little you can do about this. Whilst you could attack the beams with further applications etc. without knowing how deep the 'colouring' has occurred within the timber there is no guarantee that you would get back to a lighter colour.

I would certainly not recommend any sand blasting or any other aggressive system to remove the surfaces.

I sympathise with your predicament but would suggest that any major action now could actually cause damage to the timbers and this is best avoided.

Whilst I would not normally condone bleaching of timber it is something you might wish to consider if the colour is a serious problem. However, in all of these works I would mention that if the building is listed you should have obtained listed building consent and you may yet need listed building consent to continue with your experiments in getting the timbers to look how you intend.

Of course a major consideration in this is whether the beams were meant to be exposed timber or whether they were originally painted. In many Tudor buildings we now know that beams such as these would have been painted.

I strongly recommend that you speak to the Conservation Officer and seek specialist advice from a company that is experienced in dealing with the cleaning, maintenance and repair of such timbers (I assume them to be oak.)

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at The Whitworth Co-Partnership for responding to this question.
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SUBJECT:
Council repairs had bridged my damp proof course
FROM:
Joanne Mullen
(Yorkshire)

I have recently discovered, following repairs by the council to the outside pavement adjoining my listed property that the tarmac they used has bridged my external damp proof course, clogged ventilation bricks thus causing rain to come in and has over a period of time caused damp and rot to some floor joists. Thus my insurance company turned down my claim for repairs as they could not identify an insured peril and put it down to wear and tear due to bridging of the dpc outside. I think I read on your website about someone suing the council for something similar to this - please can you clarify my position?

Joanne Mullen

There have been a number of cases in recent years where highways departments have resurfaced roads and pavements and caused problems by increasing ground levels. In fact I am involved in one case like this at present.

The general rule is that if anyone does anything beside your property that then has a detrimental impact and causes damage to or in your property then the neighbouring owner should be asked and can eventually be made to deal with the problem and remove the cause of the damage. Of course this is a legal matter that you would need to speak to solicitors about.

When the problem relates to Highways there can be problems in that Highways Departments are generally unsympathetic.

You will need to establish that the Highways Department have indeed raised the ground level and caused problems. You will need a report from a building surveyor or someone who can state from a professional point of view what the problems are and what needs to be done to rectify the problems. You can then take this to the Highways Department and ask them to sort it out. If they refuse you can seek advice from a solicitor about legal action.

You may be able to gain support from the Conservation Officer if the building is listed because of course the work that the Highways Department have carried out is causing damage to a listed building. Arguably the fact that they have raised the ground level against the listed building is something for which listed building consent should have been obtained and it may be that the Conservation Officer could take this approach with the Highways Authority and bring some pressure to bear on them to sort out the problems.

The cases that I am aware of have never actually been through the complete process of a court hearing for a judge to make a decision that could be quoted. In the instances I am aware of the matters have always been settled out of court. However, those I am aware of have always been settled in favour of the home owner against the Highway Authority. I think the one you refer to is a case in Cambridgeshire from approximately 2 years ago. In that instance the case was settled out of court but the sum paid by the Highways Authority equated to the amount the home owners were seeking through the court anyway.

Period Property UK would like to thank Stephen Boniface, Tony Redman and other partners at The Whitworth Co-Partnership for responding to this question.
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SUBJECT:
Removing lime plaster in our stone-built house
FROM:
Karen Hearn
(Pembrokeshire)

We have problems with the lime plaster in some rooms of our stone-built house. We replastered (lime plaster) the walls several years ago as the original lime plaster was crumbling, but the same thing happened with the replacement. The walls where the problem occurs were associated with the dairy and we believe meats were also cured in this area.

We will have to remove the plaster back to the stone again, but how can we "clean" it to prevent the problem recurring?

Karen Hearn

You mention that the walls were a dairy and it is quite possible that the walls have a high level of salt contamination. Sometimes it is possible to use lime plaster as a form of poultice to draw salts out and other poulticing materials could possibly be used to draw the salts out. However, until salts are removed you will find that the plaster will continue to deteriorate and crumble away.

Where salts are a problem in buildings such as this another solution might be to create an internal wall surface of dry lining. This does mean losing some of the floor area but it avoids the problem with the walls.

I suggest you seek professional advice on how best to tackle the problem, but from what you describe I wonder if a form of dry lining might be necessary.

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