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

Ask our Agony Uncles ...

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

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

o Sealing stones Stephanie Reily-Collins (Oxfordshire)
o Deliberate debris? Nicholas Cole (Worcestershire)
o Causing havoc for no good reason Rajveen Gill (Greater London)
o A big jar of elbow grease. Rachel Weaver (Hertfordshire)
o Restrictive covenant Fiona Partington (Surrey)
o Installing solar thermal panels on a C19th semi Simon Lewis (East Sussex)
o Still experiencing damp problems Sara Eustace (Lancashire)
o Ball park thatch Michael Harper (Kent)
o Getting rid of death watch beetle once and for all Jill Wakeford (Kent)
o Bread oven fills the house with smoke Dominic Shepherd (Dorset)
o Plaster problem now worse than ever Lorraine Pretty (Essex)

SUBJECT: Sealing stones
FROM: Stephanie Reily-Collins (Oxfordshire)
I am in the process of developing a series of houses but my question is regarding a 15th century property in the middle of this development. The stones that surround the large inglenook fireplace were probably taken from the 12th century Cistercian abbey nearby. These stones are crumbling badly and I need something to seal them with. I am told that 'lime water' might do the trick but don't know where to obtain this. Do you have any other suggestions?

Added to this is a similar problem with the 17th - 18th century stone exterior walls of the rest of the development which are also very fragile and crumbly. What can I coat these with to preserve them from further decay? Some of them have been painted with 'vinyl' type paint which we are trying to remove, but with considerable difficulty.

Stephanie Reily-Collins

Whether internally or externally we would not recommend sealing them with any modern sealant. This would create an impermeable barrier, but in reality it leads to accelerated deterioration. You should remove such materials where possible and this might involve some careful experiment (in hidden areas if possible) to find the best method of removing the existing paint. Chemical removal is probably most appropriate, if handled properly.

Lime water is simply the calcium rich water which forms over the top of lime putty and can help top stiffen the surface significantly.

However it seems that you really ought to take a step back and start over. Before tackling the damage you should find out what is going on. Is the crumbling due to the nature of the stone and its age, or due to a problem (such as damp)? Is some form of coating (e.g. lime water) suitable, or has the damage gone so far that some careful replacement by a mason is necessary?

Diluted Limewash is often a suitable way of consolidating stone faces, but until the situation has been properly assessed it would be inappropriate to launch into a specific repair or coating at present.

I note you are in Oxfordshire and Richard Oxley of Oxley Conservation may be able to assist you further - his details can be found on the 'Seeking Specialists' section of the site and/or the Building Conservation Directory. As well as, or instead of, you ought to seek advice from a stone mason.

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: Deliberate debris?
FROM: Nicholas Cole (Worcestershire)
We live in a timber framed farmhouse built about 1590. We are having some electrical work done on the top attic floor which is intended for habitation. I notice that the space under the floorboards is mostly filled with dry hay and hayseed. There is a substantial amount of this material which would take days to clear out and involve lifting many ancient floorboards.

Do you think it needs to be removed? At first I wondered if it had been deliberately put there as some form of old insulation? Was this common? Alternatively the attics may have been used when it was a farm to store seed and it has simply fallen through the gaps between the boards and accumulated there over many years.

My concern is whether it is a fire or health hazard (i.e. attracting mice). So far I have found a couple of dead birds and a dead mouse under the boards. Your advice would be welcome. My inclination is to clear the bits I can get to easily and leave the rest well alone.

Nicholas Cole

Without seeing it I cannot say whether it is there deliberately or as debris. It is not unknown for such materials to be used for 'pugging' in floor voids, but I cannot say it was common because straw was always regarded as a fire risk.

That said, it is now presumably very dry and is a high fire risk. If it is tightly packed in a void it may smoulder rather than catch fire, but any form of heat or flame could be problematic.

In addition there is the health issue you mention.

Tightly packed straw deliberately used as an insulant is not necessarily a problem, but I am not sure this is what you have.

Speak to your local Conservation Officer to get a view and if it is removed remember there could be some interesting 'archaeology' in the floor void.

My preference is for its removal unless it is quite obviously deliberately installed as insulation.

I cannot see the benefit in terms of fire risk or health in removing only some of the material.

In contrast to the above comments you could take the view that it has survived all these years without a problem and now that you are aware of its presence you will simply need to take care.

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: Causing havoc for no good reason
FROM: Rajveen Gill (Greater London)
I live in a 3 storey period block of flats and my leasehold flat is on the mansard level. The freeholder's surveyor has discovered the external gutter at the top of the second floor is in danger of collapsing. The surveyor tried to get access to it from the ceiling of the second floor flat, but this proved impossible. He now wants to get to it from an internal wall in my flat.

My question is - why does this work need doing from the inside out? Shouldn't the gutter by fixed from the outside? Since the surveyor has already mistakenly attempted access from the second floor ceiling, I am concerned he might be causing havoc in my flat for no good reason.

Rajveen Gill

Without a better description or photograph I struggle to picture where the gutter is that requires internal access. My only thought is that you mean a valley gutter, or something similar, rather than a conventional gutter at the eaves of a roof.

The problem the surveyor probably has is access due to the height of the building. He would need a secure method of access in the form of a cherry picker or tower scaffold to comply with Health and Safety. The cost of this could be far greater than trying another route (e.g. through a ceiling).

If the building is listed destruction of the ceiling in the way you imply would need listed building consent and you could involve the conservation officer.

I suggest you ask the surveyor to explain precisely what he is doing, what he hopes to achieve and how he intends to do so through your flat. Without seeing your lease terms I cannot say whether he, on behalf of the managing agents/owner, has the right to demand such access. In any event, if you do give access ensure you have an agreement for complete and full reinstatement of damaged areas using traditional matching materials to the existing.


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: A big jar of elbow grease.
FROM: Rachel Weaver (Hertfordshire)

My partner and I are currently renovating our first house with council approval (a grade II listed cottage). In the living-room we have lifted the carpet and the scree underlay to reveal bricks. they are in reasonable condition and we would like to keep them. How do we clean up the floor and what would you suggest to put on top to seal/finish them?

Rachel Weaver

The simple answer is a big jar of elbow grease!

It depends what needs cleaning off the bricks as to how best to tackle the problem and if more than one material you may have to repeat the exercise.

For removing cement deposits careful physical removal and then use of chemical brick cleaning agents should leave the bricks reasonably clean.

For other materials you should experiment in small hidden areas to find the appropriate cleaner.

However, when considering cleaning try to avoid removing the simple patina of age.

As for sealing the surfaces, you may first have to wait a while. Some cleaning agents will contain salts and some efflorescence may result. Once you are sure there is no such problem a simple bees wax or linseed oil should help provide a pleasant sheen. I would not recommend anything that 'seals' the surface.

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: Restrictive covenant
FROM: Fiona Partington (Surrey)
I live in a row of 10 workers cottages. We have a restrictive covenant allowing right of way across the back of the cottages. One of our neighbours wants this changed to allow her to extend. All of the neighbours are happy to do so but want to make sure that we restrict what can be built to brick built extensions to suit the style of the property (thus making sure modern conservatories are not built) Their solicitor says this will devalue the properties. I know we can change the covenant but where do I find examples that we can use?

Fiona Partington

This is a legal matter and not something I can help you with. I suggest you look at the Discussion Forum because other questions on covenants have been posted in the past and from past threads or starting a new one you may get a useful answer.

As for devaluing the property I would suggest that a conservatory devalues the property more than a well designed proper extension and I am therefore surprised that the solicitor has suggested otherwise. The property already has a restrictive covenant and this will have a negative effect on the value anyway, what is being proposed may still have a negative impact, but not as great as the one that exists at present.

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: Installing thermal panels on a C19th semi
FROM: Simon Lewis (East Sussex)
I want to install solar thermal panels on my late C19th semi (largely out of sight, on a suitable south-facing rear roof). Eligibility for a 400 government grant towards this work ( requires that I undertake a range of energy saving measures first, including cavity wall insulation. Following your guidance on this issue I have resisted the prevailing advice to fit cavity wall insulation, but it now seems that my twin aims to sensitively restore and also 'green' my home are in conflict. Is there a way around this or do you advise that I forfeit the 400 (and lower carbon emissions!) for the better health of my house!! Limited inspection shows that my wall cavities contain debris and in places external ground surfaces are higher than the slate course - issues I intend to deal with in time!

Simon Lewis

English Heritage is presently doing much work on ways of getting historic buildings to comply with modern regulations. My understanding is that some of what may result from the EH work will be the importance of air tightness as much if not more than insulation itself.

I note a recent thread on the Discussion Forum looking at a similar topic and Nemesis has linked to another site where over a year ago this matter was discussed and a conclusion reached that air tightness was probably as important as insulation. Another conclusion seems to be that simple mass of material is important.

Back to your question, the present regulations are still in a 'trial' period and I have no doubt that as more research is done on what really matters in terms of energy performance, etc the regulations will be amended again.

If you can wait I suggest you hold back and see what comes out during the course of next year. I doubt that the grant will disappear and in any event I suspect the costs of installation, etc will come down as more people install such measures. For example, we have had more enquiries about alternative energy in the last few months to the previous year. I have been looking at solar thermal panels for hot water myself and have decided to wait until some of the dust settles.

If you really have to press on now with the work I personally would forego the 400 for the sake of the building and on the basis that what might be required now might not be regarded as such good practice in a year or so.

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: Still experiencing damp problems
FROM: Sara Eustace (Lancashire)
We have just recently bought a period property converted from 1 house into 3 flats. We occupy the ground floor flat. Although the builders commissioned a damp proof survey and DPC was applied to the walls we were still experiencing damp problems.

Following a survey we found out that the cause of the damp was poor underfloor ventilation. The surveyors informed us that they had previously advised the builders that more ventilation was required externally than was actually provided.

In the interim we are surviving using de-humidifiers in three rooms which is not a sustainable option in the long run. Can you please advise who is liable for the required works i.e. the installation of further external vents. Is it us as the buyers or the freeholder/builder?

Sara Eustace

This is in part a legal question and you really ought to speak to a solicitor.

What information have you about the work undertaken by the builder and did it come with a guarantee? What were the conditions of sale to you?

What has the builder said about sorting out the problem?

I would have thought that the builder is liable to resolve the problem, but there is the age-old 'buyer beware' issue and it depends what assurances, guarantees, replies to questions, etc were given as to whether you could pursue the builder. However, if the builder is still the Freeholder then you may be able to get the Freeholder to do the work under the terms of the lease.

My initial reaction is that the original work undertaken might not have been appropriate. However, there is really far too little information. You mention a 'survey' you had undertaken, but what was this? You also imply that the same surveyors had previously advised the builder, but does this influence their advice to you now? Have you had someone totally independent look at the problem and advise?

As a general rule I would agree that sub-floor ventilation should be good to help reduce the risk of damp problems. I would generally prefer no damp proofing on the walls as this serves to trap moisture and a damp wall will be a cold wall, therefore increasing the risk of condensation problems.

You speak of a damp problem, but as you may realise (if you have been on the Discussion Forum of this site) there are many forms of damp and without detail I cannot provide more assistance.

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: Ball park thatch
FROM: Michael Harper (Kent)
I am contemplating buying a thatched cottage in Worcestershire. The basic structure is (floor area) 15 x 30 feet plus a lean to structure on one end. It was last thatched in 1975 and re-ridged in 1992. I need a broad ball park figure as to what the cost of complete re-thatch may be - I know one can get a thatcher to have a look but I'm working against the clock and want an idea as to how much a durable re-thatch would American site gives a per square foot costing but I can't find anything comparable in UK.


Michael Harper

Thatchers work in 'squares' that is an area of 10 feet x 10feet. A very rough guide at present would be about 1,000 per square, but the cost will vary according to the difficulty of the job, demand for thatchers in the area, where you are in the country, etc, etc. Assuming your roof is about 10 squares a budget figure would be about 10,000. Start adding dormer windows and any other features that they have to thatch around and the cost increases.

I am concerned that you use the term 'durable' thatch as if implying some is not durable. Without going into too much detail there are three basic forms of thatch and two materials. There is Water Reed, and Long Straw each of which are as the name suggests Reed and Straw respectively. They are very different methods of thatching and the appearance can be very different. The third is Combed Wheat Reed, which is actually straw but laid in a similar manner to Reed, hence the name.

A lot has been written about longevity, but as the longevity of thatch depends on so many variables most life expectancy guides are fairly meaningless. All things being equal (but they never are!) one would expect Water Reed to last longest and Long Straw the shortest period, but in some circumstances and on some roofs the opposite will be true.

English Heritage publishes a free guide (see their web site) and it sets out the approach they would expect to be taken and most Local Authorities have adopted this as their approach too.

Finally, you seem to assume that it needs work. If the ridge is about 14 years old it probably will need a new ridge soon. As to whether the coats need re-thatching depends on what they are, what condition they are in, etc, etc. If you change material from one form of thatch to another you may need listed building consent.

I hope the above gives you a basic guide, but the subject is too vast for a simple answer here based on very limited information.

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: Getting rid of death watch beetle once and for all
FROM: Jill Wakeford (West Sussex)
We are nearing exchanging contracts on a 300 year old property and have been told that sloping ceilings, carpets etc have to be removed for a timber survey. This is checking an infestation of death watch beetle & woodworm. Realistically assuming all rotten wood is treated, replaced etc, what are the chances of getting rid of the creatures for once & for all? It is a four storey building with 3 small roof voids & a cellar(which houses the gas bolier in one chamber & a radiator in the other). Can anyone suggest measures we can take? We shall be arranging the survey & taking on all the associated costs.

Jill Wakeford

Let us start from the beginning. Most historic houses are likely to have had some form of infestation at some point in their life. The fact that infestation once existed does not mean there is a problem now.

To rip apart a historic building to find out whether infestation exists is not an acceptable approach because you will do more harm to the fabric than if you let the infestation continue - that is assuming you find active infestation!

It is true that the only way to know for certain whether a piece of timber has active infestation is to expose it and take a look. However, it is totally unrealistic and unacceptable to expect to inspect every timber in an historic building.

One has to assess whether there is an active problem in accessible areas and/or whether there are conditions in the property that could mean that an active problem is within a hidden area. In any event the general rule is to deal with the obvious problems first, particularly damp, and then see if this deals with the infestation.

There are many postings on the subject of timber and damp infestations on the Discussion Forum. I think you will find general horror is the reaction to the idea that you have to rip apart an historic building simply to find out if there is a problem.

With many historic buildings that I inspect where I do find an active problem if it is in a difficult to reach area, or suspected in a hidden area I often advise to leave it alone, deal with any obvious damp and other problems and manage the situation (including simply keeping an eye on it). To open up to treat could cause more harm than good. However, I would go on to say that if any work is undertaken at a future date that allows the suspect area to be opened up the opportunity to deal with the infestation should then be taken.

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: Bread oven fills the house with smoke
FROM: Dominic Shepherd (Dorset)
I have recently opened up a very large inglenook fireplace in our cottage in the woods. It has a most beautiful oval bread oven with circular brickwork. But when we light a fire the smoke just curls in at the top, filling the house with smoke, so recently I have bought an old fire hood so as to 'direct the smoke' and also to act as a heat generator as the fireplace and a solid fuel Rayburn are how we heat the cottage. I was wandering if there is an optimum height or distance between the floor and where the base of the hood should lie or is it found through trail and error. People tell me there are books written on the subject but it all sounds very esoteric and bemusing.

Dominic Shepherd

Many things affect how a fire works and even if you did find the optimum height it is no guarantee that it would work any better. Generally speaking the taller the chimney the greater the pressure difference from top to bottom and the more likely it is to work and putting in a hood does effectively lengthen the chimney slightly. However, there are other factors.

A cold fire will not draw properly until it heats up. The materials around the fire can affect how quickly it heats up and starts working properly.

A 'throat' creates a quicker air flow in part and the differential pressure results in the smoke going up the chimney. Sometimes open fires need something behind them (often shaped) to help create a form of throat.

Are there any trees or nearby buildings externally that could influence the effectiveness of the chimney top area?

Is there sufficient air flow in the room (or too much).

What you are burning can also have an impact, particularly if you are burning wood that is not sufficiently dry.

As a rule of thumb, the vertical plane in front of the opening should not be more than six times the cross sectional area of the flue for it to draw well. I assume that you have checked whether the flue is blocked by brocks or bird debris?

You need to seek specialist advice and it may be that a good chimney sweep (e.g. a NACS member) will be able to advise you properly.

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: Plaster problem now worse than ever
FROM: Lorraine Pretty (Essex)
I have an external flint wall (flint held by mortar). Inside the wall is plastered. The plaster on the inside of the wall was severely warped and broken up when I moved in about 5 years ago. My builder took out the piece of warped plaster and replastered using a waterproof plaster. The problem has now come back and is worse than ever around the area of the waterproofed plaster. The plaster has warped again and has big holes in it. There is also an area where the plaster has 'bubbled' suggesting mineralisation. My builder has recommended a false internal wall but my concern is that it is just covering the problem up and not addressing it.

Lorraine Pretty

There is too little information to provide a detailed answer.

The application of a 'waterproof' plaster is generally not a good idea. This will trap moisture in the wall.

Further investigation is needed to find out what is happening to the wall generally. If there is a build up of moisture you will need to deal with this. Although flint itself is a dense material it is important that the material around it is permeable (lime mortar, render, plaster). If moisture gets into the heart of the wall behind the flint it could cause the flint to come away and to rebuild flint is more expensive than to re-plaster or repoint in lime.

I would suggest, without knowing more detail, that you should be looking at a lime plaster to let the wall breathe.

If you find that the wall is damp anyway and even with breathable finishes there is a problem it may then be necessary to consider a form of dry lining. However, at present I would suggest that dry lining is almost a last resort.

It seems to me that you need further specific advice from someone who can inspect the property and understands the nature of the material to give proper advice.

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.