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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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...

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SUBJECT:
Breathable Floor
FROM:
Natalie Campbell
(East Sussex)

We live in a grade 1 listed, 15th century, timber framed cottage. We have significant damp problems - which we believe to be caused by \'improvements\' carried out in the 1970s, including the concreting of floors and application of cement renders to the walls. We have LBC to remove the concrete etc. However, under some of the floors we have discovered an original Victorian brick floor (presumably laid into earth) while in other places there is just earth. Our plan was to leave the brick floors as they are - however our contractor is strongly suggesting that we lift the floor, lay a breathable membrane, limecrete and then relay the floor - which I am not convinced about. With respect to the floors that are just earth I can see that there would be some benefit to doing this but surely if I then lay quarry tiles, for example, on top would this not create a barrier which would negate the efficacy of the limecrete (the quarry tiles would be in a kitchen so would have to be sealed)?

Natalie Campbell

Limecrete floors are a very useful modern use of traditional materials to create a breathable floor that can be highly insulated without the need for damp proof membranes as such. However, they are more expensive than concrete floors etc. One therefore has to be careful about when to insert a limecrete floor if considering cost effectiveness. The other issue is that if a limecrete floor is to be installed the finish much also be breathable or the benefits of the limecrete are virtually lost. Finishes that might be suitable for a limecrete floor would include any breathable surface and brick is particularly appropriate - arguably the best finish for a limecrete floor. However, unglazed tiles and other materials that will allow a degree of breathability would be suitable. If glazed tiles or any finish that is to be sealed were to be used this would negate the main benefit of using limecrete in the first place.

During a recent CPD session with a contractor/supplier of lime products the matter of limecrete floors was discussed at some length. The end conclusion (bearing in mind this was a group of professionals and contractors) was that limecrete floors were all well and good in appropriate situations but the best finish for an old existing earth floor would be brickwork.

A limecrete floor can be particularly useful if replacing a modern concrete floor where the original floors and other surfaces below have been completely destroyed anyway. They can be particularly useful if you want to install underfloor heating and retain a breathable floor structure. However, one must bear in mind that a substantial amount of excavation is necessary for a limecrete floor and if the existing floor is original one could argue that by excavating into it one is destroying archaeology. We often associate archaeology with areas outside of buildings but we often forget that an old floor in a building is a piece of the archaeology and digging through it should be treated much like an archaeological excavation.

Probably the most appropriate finish for a rammed earth floor if in generally sound condition is brickwork laid dry and tight with some of the brick dust and lime brushed into the joints but not completely filling them.

My view based on the limited information you provide, is to the leave the brick floors as they are. With regard to the floors that are earth I would suggest you consider simply laying brickwork over the top of them.

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:
Load bearing zone
FROM:
Robert Bester
(Northamptonshire)

I am in the process of renovating a 17th century listed stone built cottage and as part of the renovation and because of the grade 2 listing I will be laying a limecrete floor. I have just started digging the floors to the required levels and it is apparent by the amount of stone that is in the floor that this is likely to be supporting the walls. My questions are 1. Am I correct in assuming that the stone in the floors are supporting the walls? 2. If they are, then is it still OK to dig the floors as long as I taper the digging rather than dig straight down. I should also say I've stopped digging while I check this out!

Robert Bester

See the above with regard to limecrete floors generally.

the load spreads out and if one were to draw a section through the base of a wall and then draw lines angled down at 45° the zone below this is the zone where the load is spread.Stonework in the floor itself is unlikely to be providing any structural support for the walls. However, at the base of any wall or foundation the load does not bear directly downwards only. As a rule of thumb the load spreads out and if one were to draw a section through the base of a wall and then draw lines angled down at 45 the zone below this is the zone where the load is spread. It is generally recommended that you should not excavate into that load bearing zone without support for the wall above etc. in case it slips or subsides

Without seeing your floor I cannot say what the stone in the floor represents and without seeing the situation of the building (is it on a flat site, sloping site, top of the hill or bottom of a valley etc.?) it is difficult to say whether the stone has any more significance than simply being a floor structure. However, I would urge caution in excavating at the perimeters near the walls if this means you may be going below the base of the wall itself.

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:
Techniques to age floorboards
FROM:
Denis Shepherd
(Derbyshire)

Is there an appropriate technique to age floorboards? In our house we have 11 inch, 8 inch and 6 inch wide boards. What age are these likely to be?

Denis Shepherd

Ageing floorboards is difficult because flooring is one element of the building that is often replaced quite frequently - not simply due to wear and tear etc. Further with the insertion of services from the beginning of the 20th century onwards floorboards would have been taken up to facilitate laying of pipes and cables etc. It can therefore be difficult to age floors.

The first thing is to start with the age of the building. You then have to look at how the boards have been formed and whether they are sawn and planed or simply sawn and perhaps finished with an adze. Planed boards generally started to be used in the Georgian period but even then they were only planed on the upper visible side with the lower side being left rather crudely finished and often grooved over the joists. Softwood boards that are planed all round tend to date from the later part of the 19th century.

As a simple rule of thumb regular planed narrower boards are later (19th century on) and wider irregular boards are earlier. The nature of the timber is not necessarily a good guide, but softwood was the common material for flooring from the 18th century on.

There is no simple answer to your question because it depends on the timber that has been used, how it has been converted to form a floorboard, how it has been fixed and how it has been finished. There are many different issues that one would need to consider before deciding upon likely age for any particular board. The width alone is completely insufficient in determining the age.

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:
Work on our new old Yorkshire farmhouse
FROM:
Victoria MacDonald
(Yorkshire)

We have just moved in to a Yorkshire farmhouse which was built in 1727. It is not listed but needs some work doing on it.

Q1: what style of doors (internal and external) are appropriate for a property of this age?

Q2: the cellar (barrel roof) was flooded. We have pumped it out and apparently others in the area have drains (we are on a peaty grit stone hillside) There is no visual evidence of a drain. How feasible is it to have one bored out or should we succumb to an auto pump?

Victoria Macdonald

Q1: With a farmhouse of that period I would imagine that the doors would be fairly simple. The best guide is to go round to other similar properties in the district that were built at a similar time (whether listed or not). Looking at other properties where original doors remain will give you a much better idea of what would be appropriate than my guessing based on a rather generic national style. However, the rule of thumb would probably be something very simple.

When it comes to different elements and possible styles etc. a book I find a useful guide is one by Stephen Calloway called "The Elements of Style". There are of course many other books on style from various periods that might also be useful. You may also find that in your district there may be information provided by the Conservation Officer or other societies of people interested in historic buildings. Where I am based in Essex there is the Essex Historic Buildings Group. You could also look at the Vernacular Architecture Group and see if there are any local members of that group who may be able to assist you

Q2: If the flooding is likely to be a regular event I would suggest you consider some form of sump somewhere in the cellar with a semi-submersible pump that can pump out water as and when it enters. It may be possible to have some form of sump and pump arrangement installed and a cover placed over it so that it does not become too visible. The only disadvantage with any system such as that is that it will need maintenance and there will be a cost involved in its general running. However, for regular flood problems in cellars some form of drain perhaps with a pump is the only option to prevent a serious ongoing problem.

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:
Water ingress from the stairs above
FROM:
Natasha Perry
(London)

I own a Victorian era converted basement flat. The area directly underneath a set of stairs that lead up to the ground floor flat is becoming increasingly damp, mainly on the floor as the ceiling and walls have been tanked previously. I have had two companies assess the situation and both have said I should not be treating the damp, but treating the root cause, which is water ingress from the stairs above. My neighbour appears to have some sort of waterproof sealant (possibly mastic asphalt?) around the edges of their stairs and I was wondering if this could be a suitable solution for me? If so, what sort of companies could help me with this? If not, what do you think I should do instead?

Natasha Perry

The description in your question is insufficient to provide a detailed solution to your problem. However, knowing the type of property you are talking about there is a strong possibility that water is seeping in from the stairway above. Without knowing how it was originally formed and what finishes have been used subsequently it is difficult to give definitive guidance. However, it is quite often the case that such steps are now finished with asphalt. A good quality asphalt that can take heavy duty foot traffic should be used - this is a different quality of asphalt to that that might be used for example on a roof. It is important that it is properly applied.

If the steps do not have any finish on them and are original it may be that simply taking up the paving and re-setting it properly with tight joints and re-pointing carefully with good quality lime pointing etc. would be sufficient to resolve the problem. The main problem for me is not having any visual reference to know exactly what the situation is and how the problem may be occurring.

I would agree with the companies that you have had look at the problem in that there seems little point in trying to treat the dampness under the stair if there is a strong likelihood that continuing water ingress will simply add to the problem.

It seems likely that this can only be properly assessed by inspection and I would therefore suggest that you seek independent advice from a local building surveyor experienced in dealing with this type of property.

On a separate issue I am not sure that the work undertaken in the past has necessarily been best for the property as tanking to the walls etc. can exacerbate trapped moisture problems. Nonetheless in this instance it seems that your immediate problem is primarily water ingress from the stairs above and dealing with the matter externally is the most appropriate approach from what you have described.

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:
Finding a plasterer willing or able to work with lime
FROM:
Ann Gunning
(Merseyside)

I have recently purchased a Victorian property built in 1872 - brick construction. The floors of the old scullery have the original quarry tiles. The plaster walls of the room are in a very bad state and the plaster will need to be removed. I have been advised by 2 builders to have a dpc installed and then replaster in sand and cement and then skimmed. I did suggest to them that if we used lime plaster then there would be no need for dpc. Both said that it would be difficult to find a plasterer willing or able to work with lime. Will there solution cause me more problems and is there any other alternatives you can suggest (I have heard that Tarmac Limelite may be a compromise but will I still require a dpc?)

Ann Gunning

As I am not based in your region I cannot point you to contractors that could undertake the work but I have no doubt that in the north-west generally there will be many contractors experienced and willing to use lime plaster. I therefore suggest that you find different contractors.

You could speak to your local Conservation Officer and/or the SPAB about contractors in your region and you could even contact the Building Limes Forum for members in your region. With a bit of research I see no reason why you should have any real problem in finding a suitable contractor to deal with lime work.

With regard to Limelite it does have cement within it and is not truly breathable. I have used it in the past but generally in very specific situations (primarily cellars) where I needed something that had a degree of breathability but was robust to withstand some water pressure in certain situations. I would not normally recommend Limelite for conventional wall plastering etc.

With a property built in 1872 there is a possibility it was constructed with a damp proof course (perhaps slate or bitumen impregnated hessian). I would not normally recommend injection or retrospective insertion of damp proof courses but if the building was constructed with a DPC and it has failed for some reason this needs to be investigated further.

If the building was constructed without a DPC then provided the building is allowed to function as it was designed to (i.e. breathability) there is no reason to suspect that a DPC is now required.

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:
Constructing a fireplace using lime mortar
FROM:
Gareth Roberts
(Gwynedd County)

I want to install a heavy cast iron log burner in an old fireplace.

I have had to excavate where this burner will stand as it was very poor base. I have dug down to about 10 inches to a soil base and the adjoining walls are all in stone & brick.

I will be using a lime mortar (mix 1 lime & 4 sand) for the stone walls but I want to know what can I do with the base? Can I use concrete to provide strength? Whatever I do I will rest a large piece of slate on the slab afterwards for the burner to stand on.

Gareth Roberts

In the situation you describe I assume that the base will be contained within at least three walls and perhaps on the outer face by a hearth, therefore any mortar mix will be contained. I see no reason to include concrete for strength especially as you intend to stand the burner on a piece of slate. I would suggest that you construct the fireplace in the way you have mentioned using lime mortar (which should be 1 portion of lime: 3 sand) and bed the base of slate onto the mortar. From what you describe I see no reason why concrete has to be used. However, if you are concerned about the compressive strength of lime you could use NHL5 (Naturally Hydraulic Lime 5) as this has the best compressive strength of all the natural lime products.

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