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 (

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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: Homeowner lives with deathwatch beetle for 35 years
FROM: Rob Wilcox (Kent)
I have moved into a property (c:1700) with a longstanding history of deathwatch beetle in oak beams, many of which are hidden. Having said that, they have been here as long as I can remember (about 35yrs) and don't seem to be getting any worse.

Having read what I can find about the problem I am thinking of the following solution:

1 Put in a damp proof course (none exists at present).

2 Put in central heating (none exists at present).

3 Attack the beetle population when they are out & active by hunting them using the 'tap on the beam and home in onto the beetle's reply' method - which is great fun but perhaps not very effective and possible by using light traps.

From what I read about chemical treatments, they can be less than effective and possibly not too good for other beasties, not least of all - myself and family. So my questions are:

Am I right in thinking that these beetles will only eat the rotted softer wood and won't damage the rock-hard parts of the beams so they won't do much more real harm?

Will the measures mentioned above (damp proofing and CH) eventually get rid of the beetles anyway?

Is it worth trying a chemical treatment bearing in mind that many timbers are hidden and not likely to be exposed? If so what do you recommend?

What is the best method of attacking the population during their 'head banging season'? The property could conceivably be heated to persuade the beetles to fly. Are light traps effective? Is there a cheaper solution to the expensive Ridout trap? Does normal UV light insect zappers work or could they be adapted?


Rob Wilcox

My first reaction is - what are you worrying about? If you have lived with this for over 35 years why are you now concerned? If there is evidence of an active infestation you should investigate carefully. Now is the time of year to establish if there is activity. You seem to have read up on this and are probably aware of how to establish activity. In any event, there are plenty of postings about this on the Discussion Forum section of this site.

If the outbreak is active you should establish where the associated damp problem exists and tackle it in an appropriate manner. Simply inserting damp proof courses could cause more harm than good if not inserted in the appropriate place or with a specific beneficial purpose in mind. In any event, the beetle will generally only attack the sapwood and timber affected by rot. It cannot readily eat into the sound heartwood. That said, the very core of the timber is vulnerable and sometimes you can find that the core is eaten out, but the heartwood intact. If there are only one or two beetles, the amount of damage you cause in trying to find and eradicate them could far outweigh the damage they will cause.

  1. So, find out if the infestation is active and if so where it is and how many (you could have just one or a pair);
  2. locate the damp problem and establish the best method of tackling this (don't assume damp proofing is necessarily the best);
  3. if the property has a general 'damp' problem it might be beneficial to install better background heating, but this could take several forms and not simply central heating;
  4. if you have found the location of the infestation the UV and other traps could entice them out for you to then deal with, otherwise your efforts could be wasted if you are looking in one part of the house when they are at the opposite end;
  5. before all else, weigh up what damage has been caused and could be caused if there is an ongoing infestation against what damage might be caused by locating and dealing with the problem; 6 if there is a damp problem anyway, get it assessed properly and dealt with appropriately.

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: How do we plaster the ceiling gaps between our beams
FROM: Katrina Walker (Yorkshire)
We have recently bought a 200-year-old property, and having removed the suspended ceiling from the master bedroom, we have exposed the lovely old beams that have now been sanded and treated. However, we are wishing to re-instate the original ceiling between the beams, and are planning on doing this work ourselves. We have purchased pre-plastered boards, but due to the irregularities of the walls and beams, it is proving very difficult to ensure a good fit between measurements and installation! Certainly not without a good deal of reparative work afterwards! Is there an easier way (using this type of product) to install a ceiling that allows exposure of the original beams?

Katrina Walker

Yes - use traditional materials, or a variation thereof.

You could install laths (onto battens fixed to the 'beams' either side) and use lime plaster over them (three coat work with hair in base and second coats). Each lath would be cut to fit the gap and the plaster is simply applied to fill the area, giving a tight finish against edges, etc. Further, as lime is flexible you are far less likely to get serious cracking at perimeters.

As an alternative to timber laths you could use Expanded Metal Lath (EML). This is not such a favoured method amongst Conservation Officers, but is an alternative and certainly a better option than a board. Again a lime plaster should be used as the finish, although with EML you could use a modern renovating plaster (again frowned upon but could be acceptable).

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: What should I use render to cob wall?
FROM: Sue Welham (Devon)
I am buying an 18/19th century cottage, converted from a cowshed - the outside end wall needs re rendering. It is of cob construction.

What is the best type of rendering?

Sue Welham

I assume you mean cob construction, i.e. an earth wall?

There is no appropriate alternative to traditional lime render. Three coat work with base and second coat having hair in them. Finish with limewash.

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: Can I waterproof my Georgian cellar?
FROM: Stephen Fasham (Wiltshire)

I have an early Georgian town house (about 1730) with a large basement. One end of the basement contains a fireplace, the breast of which has been removed on the ground floor to make room for a doorway (alteration done around 1880). I would like to do some waterproofing on the basement but would like to keep the fireplace as a feature. Is it possible to waterproof the walls using a studded membrane system and then just apply waterproof render locally to the fireplace as I imagine the membrane will obscure the fireplace. The previous owners simply dry lined the walls about 4 inches off the original walls and rolled up the carpet when it rained!

Stephen Fasham

The simple answer is yes.

Be warned that the render could fail within ten years. The junctions between the membrane and render will have to be carefully formed to avoid leakage at the perimeters of the membrane. Contact the membrane manufacturers about this. The other drawback to render is that if it fails in future it could leave damaged brick faces (but there again perhaps no more damage than the numerous holes left by the membrane if ever removed).

Depending on how bad the dampness is, have you considered leaving the brickwork exposed? It will suffer moisture coming through it and you could get efflorescence on surfaces, but it is an option and probably cheaper than rendering it.

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: Longevity of reed thatch. How long is a piece of string?
FROM: Kevin Smith (Cambridgeshire)
Can anyone tell me how long a fen reed thatched roof can last for before it needs repair? The one on the house we are buying is about 20 years old and looks ok, but the thatch has settled as you would expect and the pegs are quite visible. Also how do I cure a damp patch in the clunch wall and more importantly what is a clunch wall!

Kevin Smith

How long is a piece of string?

The longevity of thatch is much debated, but it is clear that it will depend on a number of factors including:

  • the micro climate around the building,
  • its location and orientation,
  • the quality of material used,
  • the quality of workmanship,
  • pitch of the roof,
  • depth of thatch over fixings ('pegs')
  • etc, etc.

Reed thatch (I assume by 'Fen' you mean Water Reed), should normally have a life of around 60 years or perhaps longer. That said, it has been known to fail in ten years. If pegs are visible and they are not simply there to hold down netting, etc, it would seem that there is a problem. The pegs become visible as the thatch wears naturally. Once they are visible on the surface water has a more direct route into the coat and causes more rapid deterioration. From what you describe I would be concerned that the degradation of this reed is more rapid than should be the case for reed thatch only 20 years old. I suggest you have a local reed thatcher check the roof carefully. In any event, the ridge would normally require renewal every 20 years or so. It is likely to need a new ridge anyway and I suggest the thatcher generally checks the coat at the same time as dealing with the ridge.

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: How much is a BWPDA report and should I avoid free surveys?
FROM: Sarah Newman (Hampshire)
I am buying an old property and have been asked to get a full BWPDA report on this. Could you tell me a rough cost for this?

Sarah Newman

Many companies will offer a free service. I would be very wary of a free survey by such a company. It would be better to pay for an independent report. This could vary from 50 to several hundred pounds. There are various threads regarding such matters on the Discussion Forum.

The fist thing to establish is whether there is a genuine damp problem. If there is and the problem is thought to be within the wall proper testing of the wall core should be undertaken (which would push the cost into the hundreds of pounds band). Reliance should not be placed on a hand held meter for a definitive analysis of a damp problem.

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: What kind of survey do I require for a Victorian property?.
FROM: Lorraine Bennett (Greater London)
I had a survey done on a Victorian house in London and the report came back with a number of things including rising damp, air bricks which did not have sufficient exposure, damaged chimney stack. The purchase eventually fell through but, as a first time buyer, I was overwhelmed slightly, but the information being thrown at me! I am about to do a survey on another Victorian house. I am aware that houses of this age will reveal some problems but which are deemed acceptable, how do you decide whether the problems can be dealt with?

Lorraine Bennett

Get a different surveyor to do the survey!

A good building survey should identify the areas of damp, the likely causes and suggest appropriate solutions. Whilst a building survey may not definitively identify rising damp, other causes of damp problems can be identified and eliminated, as appropriate. 'Rising Damp' is a phrase that seems to be generically used for any form of damp in a wall. Other problems identified in the survey (and indeed a possible damp problem) might have needed attention and could indeed be urgent. The problem for the client is knowing how urgent or significant some of the defects might be. A valuation report will only identify matters of concern to the lender and will usually require further reports. A Homebuyer Survey will identify those matters that might have an impact on the purchase/valuation. It is only a full building survey that will not only aim to identify all defects (within reason), but give an indication of priorities and significance. Quite often I see survey reports that are really only a list of all defects with little or no context. This leaves the client confused and concerned (often unnecessarily).

It is indeed the role of a building surveyor to provide you with the advice that will enable you to decide whether the problems are such that you are willing and able to cope/deal with and indeed whether they might then have an impact on the price paid or indeed whether you purchase at all. Anything less than a full building survey could lead to more questions.

That said, the few matters you mention are not unusual issues for a Victorian property. I once had a client who had me undertake several surveys on Victorian properties. Each time I asked what was wrong with the last. I eventually got her to tell me that she did not want any property that had ever had woodworm. I explained that inactive woodworm was not a problem and even active woodworm was something that could be dealt with. She was adamant that the property she bought must not have any sign of woodworm. I therefore advised her to buy a modern building rather than an old one, to which she replied that she wanted a house with character. With some clients you cannot win! My advice to you is therefore to understand that older properties will have their problems, but many problems may have existed some time and are not a significant ongoing issue. When seeking professional advice, ensure that the professional is experienced in dealing with the type and age of property in question. When instructing a professional ensure that you are clear on the extent of advice that will be given and the nature of the report.

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: Earthy smells give cause for concern
FROM: Raymond Pring (Kent)
I have an earthy smell in my Mid Terrace Victorian house in the hallway, there seems to be adequate ventilation under the floor and no rising damp, although there is an amount of damp clay approx. 2ft. down. Should this be removed as much as possible or can I insulate with some kind of Rockwool Insulation between the joists to prevent the Earthy smell from coming up through the floor and carpets? Or can you suggest another solution?

Raymond Pring

This is a matter that can only really be addressed following an inspection. However, I can make some suggestions.

The smell could be from dampness in the sub-floor void. If this is not causing a defect (rotting timbers, etc) it may not be something that need cause concern. If it is causing damage you must find the source of the dampness and tackle appropriately.

In some houses the property is closed up for much of the day with no general ventilation. Therefore the air you come back to of an evening is the same (but stale) air you left in the morning. General ventilation may help improve the situation and reduce the smell. Have you got exposed floorboards? If so, the smell may be a normal smell (i.e. no problem), but getting through to the rooms via the gaps between boards. Covering the floor, closing the gaps, insulating under the floorboards - any of these may help. If you insulate make sure that there is good ventilation under the boards (through the void).

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 remove my cracking render in exposed location?
FROM: Vicky Thirlwell (Cumbria)
The front (only) of our 1800's red sandstone farmhouse has been rendered in the late 60's with cement render. This appears to have been applied over the many layers of limewash which were previously there. The top layer of render is cracked and small areas are coming off. What is the best way to remove this render? Would you advise this? The Stone arch over the front door appears to have been painted black with a bitumen like substance, how/can this be removed? Internally the wall has been plastered in a cement plaster so hard that we need a drill to hang a picture! We were planning to hack off the internal plaster and replace this. The sandstone is fairly soft, but we are on the border between sandstone and limestone areas, and some limestone has been used around the property.

Vicky Thirlwell

If the render is over limewash you will probably find that much of it is poorly adhered. If this is the case it should come away quite easily. Find a loose area and then carefully lever it off by pushing a bolster chisel behind it. Continue doing this across the face of the wall. Where the render is adhered carefully chip it off with the bolster at the edge. It would be best to experiment in a small area that is not highly visible. If successful continue as far as you wish.

The removal of the render may cause damage to the stone behind. Until the work is undertaken you will not know what damage will actually occur. It is quite possible that the damage caused by removing the render will mean that some form of finish will need to be applied to the stone.

In Cumbria you may be exposed to weather and this may explain why the render was installed. If the stone had many layers of limewash behind this indicates that weathering may have been a problem in the past. You could re-render (with lime render) or try limewash in the first instance and render later if better protection from weather is found necessary.

Given a choice between achieving a breathable surface on the exterior or on the interior I would nearly always go for breathable exterior faces. I therefore suggest you concentrate your efforts on getting the exterior working as it should (breathable) and not be too concerned about the internal faces. Ideally the internal cement render should be replaced with lime plaster, but this is perhaps not so important. That said, if you have the funds and inclination to deal with the interior be careful not to cause unnecessary damage, but otherwise get on with it.

The best way to remove the bitumen paint is with a chemical system - see Strippers in the 'Seeking Specialists' section.

These old buildings work best if the walls are allowed to breathe. Nonetheless, be warned that in some exposed locations a breathable wall can mean some dampness. In this instance I would hope that a suitable lime wash and/or render should give sufficient protection externally.

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.