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 Determined damp patch Emma Sheward (Staffordshire)
o Cleaning a lime ash floor Amy Dinsdale (Devon)
o Structual movement David Fletcher (Suffolk)
o Rain ingress David Howes (Suffolk)
o Noises from the loo Dillian Warman (Wiltshire)
o Foil backed wall paper. Jake Barlow (East Sussex)
o Replace the roof or not? Helen Slack (Yorkshire)
o Damp ... again Stephen Flint (Oxfordshire)
o DPCs Kate Williams (Wiltshire)
o Investigating a damp problem Geraldine Timlin (Hampshire)
o Care for chalk cob cottage Louise Payne (Devon)
o Wallpaper stripping Alan Newland (Greater London)
o Re-housing bats Sarah Else (Greater London)
o Sealing timber and brick Karen Norton (Shropshire)
 

SUBJECT: Determined damp patch
FROM: Emma Sheward (Staffordshire)
I have an 1890 Terrace. When I moved in I had a damp-proof course fitted. On the interior wall (stair wall with cupboard underneath), the plaster was hacked off to 3ft, which is now perfect, but above this new plaster, the old plaster appears to be damp for another 3ft up. I have just installed Central Heating as the house has had no heating except for one gas fire. I am having problems painting this wall; every time I paint there is a big damp patch that stays on the wall. Can you suggest any type of paint that will cover without the marks coming through? I am hoping not to have to re-plaster yet...but is this my only option?

Emma Sheward

There is insufficient information here to give a definitive diagnosis.

It is a well established fact that the render system used after damp proofing works can simply trap any residual or later moisture in the wall. Over time this could build up and appear above the top of the render. A possible solution may involve complete removal of the render to let the moisture in the wall escape. Once the wall has dried you could consider re-plaster, but I would suggest a lime plaster to allow any further/future damp escape without hindrance.

Another possibility is that it is not damp as such, but hygroscopic salts that are simply absorbing moisture and 'wetting up' to appear as a damp patch. Again the solution may involve extensive re-plastering. There is a possibility that the damp could be due to leaks. You should find out where pipes run and establish whether this might be a problem.

It could be moisture from a leak in the neighbouring property and you should liaise with your neighbour over this possibility.

As you can see, there are several possible reasons for the problem and the above does not include all of the possibilities. You should find an independent professional experienced in diagnosing damp problems and have the area investigated (possibly test samples from the wall) and have appropriate work undertaken. However, from what you describe I doubt you will get away from the need to undertake some re-plastering.

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: Cleaning a lime ash floor
FROM: Amy Dinsdale (Devon)
We have a lime ash floor which has remains of lino and rubber carpet backing stuck to it. We want to clean the floor but are not sure how to - can we use warm soapy water and a scrubbing brush or is this a specialised job?

Amy Dinsdale

A lime ash floor should withstand gentle cleaning and water being used on it. Just be careful and try a small area in a corner first. Lime ash floors are a very specialised area of work and you should contact SPAB for details of those in your region who may be able to give specific 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.

 
 
 
 

SUBJECT: Structural Movement
FROM: David Fletcher (Suffolk)
I've just had a building survey done on an end terrace property (circa 1900) and there is 'evidence of structural movement'. Plaster work is cracked on internal wall and corresponding brick on external wall is also cracked. The adjacent wall also shows signs of movement with distortion to window and door frames. The suggested next step is to involve a structural engineer. What will a structural engineer be able to conclude from a visual inspection that the surveyor couldn't?

David Fletcher

If the building survey was undertaken by a competent building surveyor I cannot see why the initial diagnosis could not have been made by the surveyor. In short the answer to your question will be nothing, other than bring to bear knowledge and experience that the surveyor did not have.

Question the surveyor further. Is there evidence of recent or active movement and what makes him/her suspect an ongoing problem? If there is real suspicion of a problem get the vendor (I assume you are buying) to submit an insurance claim and they will get investigation, etc undertaken (involving engineers as appropriate). Once the claim is in progress get the claim transferred to you when you buy.

In assessing movement problems an engineer comes into his/her own during the investigation and when designing structural repairs (although some building surveyors can do this also).

If the surveyor was simply unable to make an assessment, I would question why he/she is undertaking full building surveys? However, if you had a Homebuyers report the approach you outline the surveyor has taken is perhaps more understandable.

Many engineers I deal with are fed up with having to advise on cracks and problems that a competent surveyor should be able to deal with. When it comes to general crack and structural movement assessment a building surveyor (undertaking a building survey) and an engineer should be equally competent.

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: Rain ingress
FROM: David Howes (Suffolk)

We extensively repaired our 16th Century timber frame house five years ago but we still have problems keeping rain out of one of the windows. The window faces NE and gets the worst of the prevailing weather. The frame slopes quite badly so the rain runs down the front of the house and straight through the first floor window. I have tried tubes and tubes of gunk and still it gets in. Someone has suggest a board above the window but I'm not sure how to progress this. Any suggestions?

David Howes

Wind driven rain can get into very small, almost invisible, cracks and gaps and find a route through. You should find the area where it is really getting in. I have found that the best way of finding a problem such as this is to wait until dry weather and get a hose out. With one person inside and another outside gently and slowly play the hose around the window until you find the point where water comes through. Investigate the area and repair accordingly.

With many historic buildings the junctions between windows and the walls are sometimes poorly detailed. This is often the case where windows have been changed (e.g. Georgian windows in an earlier timber framed building). Sometimes it is possible to deal with problems by adding hoods, flashings, aprons, etc around the window. However, sometimes it is necessary to carefully remove the window and reinsert but with appropriate detailing (usually in lead) to provide protection at the perimeters.

Using mastic can help, but usually only as a temporary measure. One similar problem I once dealt with (in a modern flat) was due to the mastic itself having a hairline split and letting water in!

In looking at this problem ensure that all other sources of potential water over the window are dealt with - check gutters, downpipes, overflow, etc, etc. Make sure there is no other source of water. If you do fit a hood rather than face fix (and risk water getting between the hood timber and the structure it is fixed to) you may have to open up a small area and insert the hood so that water runs down and over it away from the building and any joints rather than into joints, etc.

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

 

 
 
 
 

SUBJECT: Noise from the loo
FROM: Dillian Warman (Wiltshire)
We've exposed the rafters in the original kitchen as we're building a small extension and wanted there to be some character. My panic is that when I was cleaning up after the builders I could hear my husband using the upstairs loo! Toilets seats up and down etc. etc. In the bathroom it is laminate flooring with the usual underfloor "stuff" and before the plasterboard was put between the rafters, the space was stuffed with the yellow insulation that they put between the building blocks and the stonework.

What can we do to rectify this situation?

Dillian Warman

The insulation is doing very little, as the sound is being transmitted by the floor and joists (a bit like a drum skin). You have two choices. Take up the floor in the bathroom (and bath suite, etc) and lay an acoustic material down before you lay the floor finishes. This will help deaden sound and help reduce the floor behaving like a drum. The alternative is to put up a false ceiling in the room below and again put an acoustic isolating material between the ceiling and joists.

Unfortunately, if you want a boarded floor and exposed joists below you will have the noise problem and there is not much you can do about it.

Look at the discussion forum of this web site because there have been quite a few threads about noise problems in houses and between houses.

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: Foil backed wall paper
FROM: Jake Barlow (East Sussex)
Have hydroscopic salts that very slowly but surely re-occur on the inside of second floor stair well. Had wall checked on the outside for cracks but no render blown. Had the outside treated with chemical seal just in case.

Plaster not blown on the inside and doesn't feel or smell damp. No mould that would indicate moist but salts keep recurring.

Damp specialist recommended applying foil backed wall paper to the wall. Would you agree that this was the best solution. If yes could you recommend a good product to use. Doesn't seem to be very readily available.

Jake Barlow

Without inspecting I cannot be too specific. However, I would not recommend foil backed board - this merely masks the problem. It is possible that there has been a past problem and the plaster has become 'contaminated'. It is likely you will have to re-plaster even though it may not be hollow or unsound at present. You may not have an ongoing water penetration or leak problem. Sometimes salts can take years to come out. Nonetheless, you should carefully check and ensure that there is no source of damp (hidden pipes, flue voids, etc).

If you have read this site (particularly the discussion forum) you will find that sealing the walls can cause more long term problems than they cure. In this case a liquid applied sealant will probably leach out after several years, simply do not re-apply.

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: Replace the roof or not?
FROM: Helen Slack (Yorkshire)
We are currently renovating and extending our house (built circa 1820) and are unsure what to do about the roof. Surveys have shown that the traditional oak timbers and purlins have been infested at some point, but we get differing opinions on whether to replace the roof or not. All parties agree that the existing tiles are too heavy and need replacing-but where one structural engineer will say that we may as well change the timbers too another will advise that if treated for infestation the oak timbers will still be stronger than anything used currently for roofing.

Helen Slack

You don't say what type of 'tile' you have. If the roof is of Oak and there is suspicion about strength, I suspect you have a stone slate roof. These can be very heavy.

You mention replacing the 'tiles', but it is not clear whether these are modern tiles that you are changing to something else or whether they are old tiles that you are simply taking off and putting on again. In any event, if the property is listed you should speak to the Conservation Officer about getting consent.

If the infestation is active, but you have had it treated (or will do so during the work) the damage is unlikely to worsen significantly in years to come. Therefore the roof strength will be roughly what it is now. Is the roof showing signs of stress, distortion, weakness, etc? If so, it may well be the case that it requires strengthening and/or repair. However, there are various means of dealing with this. Quite often a roof structure can be strengthened in situ.

If the roof covering is to be removed (even if it is being salvaged and reinstated) the roof structure will be exposed and at this point it would be quite straightforward to repair and/or strengthen, as necessary. If the roof covering is to stay in place it is often possible to careful insert strengthening pieces, etc and bolt them alongside existing timbers.

Some engineers recommend simply replacing the frame because it is the easy option. This does not mean it is the only option. I suggest you go back to the engineers advising and ask them to properly justify their suggested approaches before deciding what to do.

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

 
 
 
 

SUBJECT: Damp ... again
FROM: Stephen Flint (Oxfordshire)
I am sure you receive countless enquiries regarding damp, here is one more for the bag...

I have 200 year old cottage constructed from Horton stone which we purchased 1 year ago. We were aware of a damp patch on an internal wall where the paint was flaking. The garden is approx 1 metre higher than the solid floor level. There is a newer extension at right angles to the wall in question, the internal floor has been replaced in the last 5 years, although the original quarry tiles remain in another room that does not suffer with damp. There is a waste water drain that corresponds with the damp area. On excavation around the drain I could locate no leaks, although the ground surrounding it is clay and is very wet at a depth of 1/2 metre. Some of the mortar looks to have broken down ( or even be none existent! ) and there are areas where water looks to have penetrated. I proposed to further excavate around the drain & along the wall, repoint where necessary with the correct mortar, lay slate against the wall to encourage water to run off & finally fill the trench with pea gravel to aid drainage. After reading some of your articles this seemed like the most appropriate course of action or should I seek professional advice also?

Stephen Flint

I think you are certainly along the right track.

If appropriate and practically possible I prefer to simply clear the ground away and leave the wall exposed. This usually means creating a retaining wall set slightly away from the house (100-150mm away) and finish the earth against it (remembering to put in drainage holes, etc). The gap between the house and the new retaining wall should be left open with the base draining to ground (perhaps some shingle/gravel in it). However, you need to ensure you can get in to the gap to clear of blockages occasionally. The top can be finished by cantilevering paving slabs over, by a grille, etc, etc.

If you prefer to build the earth up back against the wall (against a slate vertical surface) you need to ensure the slate is fully bonded to the wall with lime mortar to remove the risk of gaps for moisture to rise by capillary action. You should also fill the full height of the gap between the earth and the slate with gravel/shingle for about 100mm away from the wall to create a drainage strip (full height). To prevent the earth eventually combining with the gravel I suggest you insert a geotextile membrane vertically between the earth and gravel.

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: DPCs
FROM: Kate Williams (Wiltshire)
As a heritage development officer for a District Council, I get numerous queries re. DPC's in Listed Buildings. This particular Grade II Listed property has suffered from damp due to a variety of reasons - all of which are being addressed and the building will be allowed to dry out. Despite this, the owner still wishes to install a DPC, which will involve the temporary removal of the stone flags (which I suspect is laid directly on the earth) that run through the ground floor of the property. Is there any lime based/alternative but sympathetic DPC that can be used as an alternative to the more harmful chemical injection/tanking etc?

Kate Williams

Not that I am aware of.

The insertion of a chemical DPC alters the character of the material in that it alters the characteristics in terms of the performance of the material. The insertion of a dpc therefore should normally require listed building consent, which no doubt you will refuse.

If the owner is going to the trouble of creating a breathable structure, etc why are they then ruining the effect by pumping a pointless dpc chemical system in the walls? If a positive barrier is created at all the moisture will find another route. Even if the rest of the structure is breathable it is likely that certain areas near to the inserted DCP will become 'supercharged' with moisture. In future years there could be another damp problem, only by then the injected DPC will be there and is irreversible so any future solution will have to involve yet more invasive work.

Without knowing more detail about your specific situation it is difficult to advise further. I note that you are in Witlshire, have you spoken with Linda Jubb, a Chartered Building Surveyor working as a Conservation Officer for North Wilts (I believe)?

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: Investigating a damp problem
FROM: Geraldine Timlin (Hampshire)
I live on the top floor (3rd) of a Victorian conversion. My downstairs neighbour has damp penetration to a room which lies directly below my roof terrace. The neighbour's room is exposed on three sides. Two years ago, on his advising me of damp problems I contacted the Flat Roofing Association for advice and guidance. With the information I got I had the roof stripped and retiled with a porous tile and no grouting and all the edges were sealed as suggested.

Two weeks after the new roof terrace was laid my neighbour reported further damp penetration. The roofer returned and found no evidence of a problem with the terrace. My neighbour brought in an expert (surveyor/engineer?) who said that the terrace was a good job but that the brickwork of the whole back addition was likely to be porous and should be sealed. When my neighbour pointed out some small fissures (0.25mm) above the level of the asphalt plinth (skirting) the expert said this could be a contributory factor. These have been sealed.

However, my neighbour does not want to accept this solution but prefers to insist that the roof terrace is at fault. I am reluctant to rip it up and pay for another roof job only to find that he is still experiencing the same damp problems. This is becoming stressful and acrimonious. Will sealing the brickwork help? Do you have any other suggestions?

Geraldine Timlin

Yes, investigate it properly.

I would not suggest sealing walls, etc for reasons that have been discussed many times here and on the discussion forum section of this site. However, if pointing is defective it should be made good (with lime mortar).

I suggest waiting till dry weather and trying a hose test (see the earlier advice regarding a leaking window). If done carefully this can be a useful non-invasive method of finding leaks.

It is unlikely you will need to take up the roof, etc (and if you did surely you would have some come-back on the contractor?). I suspect that careful investigation will help identify the precise location at which water enters and this will enable appropriate repair to be undertaken.

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: Care for chalk cob cottage
FROM: Louise Payne (Devon)
I have just bought a chalk cob cottage and would like advice on how to care and maintain it on both the outside and inside.

Secondly, I know it's supposed to be slightly damp but some of the paint inside is peeling - what can I do?

Thirdly, we want to redecorate can you suggest what paints we should use and any other preparations we need to make.

Louise Payne

I can do no better than refer you to the guidance note on the IHBC web site found at http://www.ihbc.org.uk/Cob_Paper/cobindex.html

With regard to the peeling paint, if the render externally is modern non-breathable, etc moisture could be trapped in the wall and this could be the cause of a problem. Alternatively, the paint internally may be impermeable and over time the moisture in the wall has caused it to peel. The answer is to use permeable paints (e.g. 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: Wallpaper stripping
FROM: Alan Newland (Greater London)
Should we leave wallpaper which looks 90% OK rather than risk damaging the wall plaster by taking the paper off?

The building is an 1860 terrace house in South Kensington. It would be in the best interest of the managing agent and contractors to re-paper the 4 levels of the staircase. Some decorators and a plasterer have said wall plaster of goodness knows how old, might have deteriorated and if a lot of it then needed repairing due to removing the paper, it could add considerably to the cost of the re-decoration. Payable of course by leaseholders. The m/agent's contractors have refused to give an undertaking not to charge extra if they damage lots of plaster. I have been unable to find written evidence of how stable or unstable wall plaster is likely to be in buildings of this age.

Alan Newland

It is not unusual to find that the wallpaper itself is helping to hold the face plaster in place. Quite often when the paper is stripped the full extent of plaster damage is revealed and much more plastering is then required. I therefore understand your concerns and think you are justified in anticipating higher end costs.

I would suggest that this is a judgement call. If the paper and plaster appears to be generally sound and you could improve the appearance merely by painting over the paper (or leaving alone) then this would seem the most sensible approach. However, it sounds as if there are several other occupiers and this ought to be a joint decision based partly on the present appearance (is it acceptable, what really needs doing?), the likely extent of increased work (costs, etc) and the end result (can you live with the present finish improved or is it so bad it really does need more major work?).

Unfortunately, the condition of the plaster will depend upon many factors, including how well it was applied in the first instance, how much water damage has occurred over the years, what other damage has occurred in the past, what effect heating has had, etc, etc.

Perhaps once the area has been fitted out with access scaffold (or ladders, platforms, etc) the walls could be gently tapped to establish how much of the plaster seems hollow and therefore get a rough idea of how much re-plastering may be required and the likely cost thereof.

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: Re-housing bats.
FROM: Sarah Else (Greater London)
We are currently in the process of buying a period property in Norfolk which comes with a barn as part of the outbuildings. The barn has bats nesting within it. We are aware that they are a protected species however, we are hoping to renovate the barn to live in and need to re-house the bats. Is this possible and how do we go about doing this so the bats are safe and protected and not traumatised?

Sarah Else

Yes it is possible but you need to be very careful.

Speak to the Bat Conservation Trust who can be found at http://www.bats.org.uk/

There are various local groups and they advise on such matters.

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: Sealing timber and brick
FROM: Karen Norton (Shropshire)
We have a 300 year old grade 11 listed cottage with timbers on the outside with brick in-fill. With heavy rain we have water coming into the house through the timbers and would like to know how to seal the timber and brick on the outside to avoid this happening again (we appreciate that the timbers move with the different climate changes).

Karen Norton

This is a common problem. Many timber framed houses were never built to have the frame exposed. If this is the case the problem can be awkward to sort out. However, the best method is to simply coat the whole elevation (frame and panels) with limewash. The limewash gets into the cracks and fills them to become a lime 'packer'.

However, I suspect you may have a cement render and may have painted timbers. If this is the case the long term solution is to remove the render, strip the timbers of the paint and re-form the elevations. The render should be replaced with lime render and the limewash then taken over the whole, as mentioned above. The limewash can be brushed off the timbers to give a bit more of a colour contrast it you wish to do so.

As a temporary measure you could fill the gaps, cracks with sealants, but I can assure you that this will merely accelerate the degradation of the timber, so is a bad idea.

If there is evidence that the frame was once completely covered you could consider introducing a covering, such as render, weatherboard, hung tiles, etc, etc.

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