Ask our Agony Uncles ...

SUBJECT: Cleaning Victorian floor tiles
FROM: Colin (Cheshire)
How do I go about cleaning original Victorian floor tiles (unglazed) to restore their colour. They appear to be physically sound but have become dulled and heavily grimed from years of lack of care.

Colin

The Society for the Protection of Ancient Buildings (SPAB) recommends that Victorian floor tiles are cleaned with minimal quantities of warm water or warm water with a little neutral, sulphate free detergent to remove more tenacious marks. The use of caustic soda or hydrofluoric acid is not recommended because it can damage the fireskin of the tile and etch the surface of the tile. Although, on this occasion it sounds as if the surface of the tiles are already damaged and the use of some diluted floor cleaning acid may help you remove marks which have become deeply ingrained in the damaged surface. To bring out the colour in the tiles beeswax and turpentine polish can be used. The use of linseed oil should avoided because it yellows with age and absorbs dirt which may further darken the tiles. The use of Danish oil has also been suggested to me in the past, but as yet I'm yet to try this particular technique. Finally, what is under the tiles. If they are simply laid on earth you could try to reverse the tiles? And, of course, when applying polish try it out on a small section of floor first to determine the exact affect on the tile surface.

SUBJECT: U-value for wattle & Daub
FROM: Paula Harber (Near Bury St. Edmunds, Suffolk)
Hi Malcom, you will be pleased to hear I am currently repairing my 15th wattle & daub panel to date. My question is do you know the U - Value of wattle & daub? I would like to build a small green oak extension and infill with W & D, using limewashed oak lap-boarding externally if possible, but have been told the U - Value would not be up to building control standards. However, no-one can tell me officially what the U-V is! Can you?

Paula Harber

Paula, the problem you are faced with is one that many of us working in the conservation building industry are faced with on a daily basis i.e. the general insistence by various regulatory bodies that building materials used in new build construction must meet modern day levels of insulation to help prevent heat loss and energy wastage. Presently, the only research that has come to my attention was undertaken by Bournemouth University which showed an 18'' cob wall to have a U-value of 0.6. For those readers uncertain of such terminology a normal cavity wall roughly has a U-value of 0.35 and the lower the figure the slower the movement of heat energy through the material. Ironically, the Government's bid to show its green credentials by helping to conserve energy has delivered a blow to any attempts by people using traditional materials and techniques to build new build structures traditionally. Perhaps, the Government should be more concerned not only with the energy loss through materials used in construction but the amount of energy used to make such materials. If such a 'lifecycle' approach was adopted such materials as daub would rise to the top of the podium. On a final note, Building Inspectors do have some discretion and can allow certain structures to go-ahead despite their failure to strictly adhere to regulations. But, to achieve such a goal, which will be difficult, you will need a Conservation Officer to convincingly argue your case and a Building Inspector who has an understanding and appreciation of traditional materials and construction.

On a final my favoured solution for new build using natural materials is to infill timber framing, with a clay lump cavity wall filled with wool insulation. Then render the structure in lime.

SUBJECT: Where to look for rotten nasties
FROM: James McAteer
I am considering purchasing an ex local authority building, circa 1895. It has just been C Listed (Scotland). It has been empty and unheated for 18 months, hence it has lost some ceiling plaster and may have some dry/wet rot. The exterior and roof look good. May be very slight subsidence. Sash and case windows are a bit rough. My main concern is about the extent of the rot. What questions should I ask a surveyor to be sure that he will look in the right places to discover all the nasties that could add to the renovation costs?

James McAteer

James, firstly if you ever have to advise a surveyor of where to look for areas possibly suffering from either wet or dry rot then you've got the wrong surveyor. Therefore, my first tip is to ensure any surveyor you use has an understanding of older properties and how they work, as well as possibly some form of qualification in conservation. Two key conditions which allow rot to thrive are prolonged dampness and lack of ventilation - these two conditions help to indicate areas of investigation.

Secondly, some of the key areas to look out for rot are as follows assuming the property in question is built from stone. Firstly make a visual inspection of the roof. Look out for dips and depressions in the roof and possible spreading of the roof structure. Particular attention needs to be made where the rafters meet the wall plate or walls, as well as, the condition and strength of the ceiling joists supporting the water tank.

On the floor and ceiling joist front, if possible, examine where the ends of the joists enter the walls. Water penetration over time may had lead to the tips of the joists rotting leading to excessive 'springing' of your floorboards. On the window front do not be fooled by shiny new white paint. Feel and prod firmly the ends and undersides of the sills and the areas where pieces of wood have been jointed together. Particularly, where the uprights of the windows meet the sills. Don't be surprised if you find areas completely covered by paint which are soft and decaying underneath. Also take some time to examine the skirting boards using the same method.

Finally, rot requires damp and lack of ventilation to thrive. By correctly heating your home, improving ventilation and undertaking various repairs to stop penetrative damp e.g. replace slates, rot can be stopped. And, of course, if you use skilled craftsmen they can remove rotten pieces of timber and simply splice on new members without having to remove and replace a whole window. Sadly, simple repairs are being replaced by the modern day systems approach of replacing a whole system rather than simply repairing the faulty component.

SUBJECT: What no dpc?
FROM: Jason Chambers (Keswick, Cumbria)
We are looking at buying a property in Bothel, Cumbria. The property in question is a old Forge which is 100 year plus old. It has recently been renovated and we paid for a home buyers report on the property with the Cumberland Building Society. The survey says there is no evidence of a damp proof course. Is this something to be concerned about ?

Jason Chambers

Jason, most old buildings have solid walls and no damp-proof course. Therefore moisture was readily absorbed into the fabric of the property, but this was countered by open fires drawing copious amounts of air through loosely fitting windows leading to a high rate of ventilation and moisture simply evaporating away. Should you be worried that your possible new home has no evidence of a damp proof course. Well the answer is 'no' you should not be concerned about the lack of damp proof course. But, you should be concerned if the building society insist on a damp proof course being installed in a property which is not suffering from damp. This is because some professionals argue that rising damp is a myth and the majority of damp problems can be solved by improving the ventilation of your property, using breathing plasters, ensuring guttering and downpipes are not leaking and that the ground level surrounding your property is lower than the internal floor. For a more detailed review read the article by Stephen Boniface entitled 'Mortgage Surveys of Historic Buildings' in the 'Information' section.

SUBJECT: Back to school at 'The Lime Centre'
FROM: Helen Pitel (London)
I have been quoted the enormous price of £4,500 just to have 3 walls of my kitchen re-plastered with lime. I can't afford that - so is this something I could DIY, going for a rough finish? Or could I use clay instead? The house is Cotswold stone 1840. I also need to patch some lime plaster where the house has been rewired - is there a suitable lime version of Polyfilla I could use?

Helen Pitel

Helen, if you are prepared to plaster your kitchen with a so-called 'DIY' lime plaster replacement why not simply use lime plaster and do it yourself. If you are prepared to go to all the time and effort to undertake the plastering simply use the correct material i.e. lime. Your first port of call is to seek some beginners guidance and tuition. Contact Bob Bennett at The Lime Centre in Winchester on 01962 713 636 or email him on bob@limecentre.co.uk. The Lime Centre in Winchester runs 'Lime Days' which will provide you with the basics concerning lime mortar, lime plaster, lime render, limewash, rendering and pointing. They can also supply you with necessary materials. With the money you save by undertaking the course and finding out if you can do the work yourself you can then enjoy a few weeks in the Maldives - if you do the plastering - to relax those aching limbs.

SUBJECT: Derelict wreck next door undermines my confidence in buying dream cottage
FROM: Anita Omatseone (Essendon, Hertfordshire)
I'm about to embark on the purchase of a grade II listed property in Yorkshire. There is a parking dispute but I've decided to go ahead anyway as the worst that can happen is that I share my drive with the adjoining house. There have been problems with selling the adjoining property due to the parking situation. The whole property was one split into two - my portion of the property is the smaller of the two, but has the greater proportion of land. I am slightly concerned that if the parking issue is resolved in my property's favour, the other house may be empty for some time. If this is the case what are the pit falls I should be aware of in regards to living next to an adjoining empty property. There is also a private bore hole for water serviced by the local stream. The arrangement is that I pay 66% of the maintenance charges on the supply and my neighbour pays electricity for supply. I don't know anything about water supplies and would appreciate any warning signs I should get my solicitor to check.

Anita Omatseone

Depending upon its precise location, the major pitfalls will be much the same as living next to any empty building e.g. vandalism, neglect of the neighbouring property (e.g. roof, gutters, etc.) that could result in leaks into your property. Periodically check the exterior of the neighbouring property and ensure you have a contact name and number for the owner should you need to get hold of them regarding repairs, vandalism, etc. Regarding the services, this needs careful handling. Assuming the neighbouring property is empty they should not use any services and should not incur any charges, other than normal standing charges. You should ensure that you have a contact point and agreed method of payment for standing charges, etc. so that you are not out of pocket. Regarding the electrical supply, I suggest you look at taking over the main payment and seek the standing charge contribution as mentioned above. This gives you total control. There is of course a risk that the neighbouring owner does not pay their contribution, but you must weight this against the risk of having the services disconnected altogether! You could also look into having the services completely separated. The water supply should be fitted with filters, etc. to purify it and these will probably need to be checked every six months or so. The purity of the water would usually be checked by the Water Authority periodically (6-12 months). If the present filter, etc. is next door, have it moved or have additional filters fitted in your property. Similar comment would apply to any pump. Make sure that if the neighbouring property is left vacant they do not turn off the common supplies to your property!!

Period Property UK would like to thank Stephen Boniface from Boniface Associates for answering this question.

SUBJECT: Something damp under the stairs
FROM: James Meek (Hackney, London)
We live in a maisonette on the basement and ground floors of a grade II listed late Georgian end-of-terrace house. Our internal stairs come down against the gable end wall; there's a large walk-in cupboard underneath the stairs, with the entrance through the bathroom. In the corner of the cupboard, where the outside wall meets the bottom of the underside of the stairs, there's an area of damp. I suspect it may be moisture from our showers condensing on the cold outside wall. At that point the wall is below ground level on the other side, so I'm not sure ventilation would help, and we can't cut a hole in the stairs. I was wondering if there was any kind of non-mechanical way of dealing with the problem - some kind of chemical sponge to sop up the moisture?

James Meek

Not that I am aware of. Anything that simply soaks up the moisture will need emptying/drying otherwise the moisture remains on site and continues to pose a problem. This is often the case with the portable dehumidifiers, as they simply store the water in them and do not remove it completely. Even if you use crystals to absorb the moisture these will need to be replaced or dried once saturated. Any such method therefore involves high maintenance. You should look at the ventilation of the bathroom. If this is the source of moisture (most likely), you must ensure that the moisture is removed from the bathroom more speedily and efficiently than at present. Another possibility is to install a small heater in the cupboard to raise the temperature above the dew point. I am not convinced that this alone will resolve the problem as there is always a risk that a time will come when the temperature drops below dew point and condensation recurs. A form of positive ventilation will probably help, even though the area is below ground level, as it ensures that the moisture is removed before it can form significant levels of condensation, etc.

SUBJECT: Flue deposits possibly lead to damp?
FROM: Terence Heath (Cheltenham, Gloucestershire)
Property is 1880 solid brick, semi-detached 3 bed house. In 1994, a Renovation Grant was provided for extensive work by local council. This was carried out by a builder under supervision of surveyor [ARICS] appointed by Care & Repair [Cheltenham] Ltd acting as our agents. All this was required by the council. We find that we have the two rear rooms, kitchen and bedroom above, showing black patches on the walls and despite washing them off, they reappear. A builder whom we consulted says that the patches will always return as they are due to the grant works leaving bad bricks in the wall and using cement rendering internally instead of re-plastering with Renovation Plaster. Are you of the opinion that this is the correct explanation and what course should we take, please?

Terence Heath

This is a problem that can only be properly assessed by physical inspection. Did the gable wall once include chimneys? If so, is the staining the residue from the old flues? Alternatively the staining may be due to condensation? I am not sure what the builder means by 'bad bricks', but he could mean bricks that have been contaminated, perhaps by flue deposits. It is possible to seal the surfaces with appropriate render/plaster systems, but in some extreme cases the bricks have to be physically removed. You should ask the original surveyor to return to investigate and resolve the problem; that is his job. Alternatively, or as well, you could seek independent advice from another surveyor, preferably one experienced in dealing with older buildings and might have come across the problem before. My long-distance assessment is that you either have a condensation problem - therefore you need to improve the ventilation in the kitchen - or some form of contamination of the bricks that is now grinning through the surfaces. Sorry I cannot be more specific.

Period Property UK would like to thank Stephen Boniface from Boniface Associates for answering this question.

SUBJECT: Grants & alterations without listed building planning consent
FROM: John Hall (Farnham, Surrey)
What grants are available for Grade II listed buildings and could you explain the consequences of purchasing a property which has alterations undertaken by the previous owner without listed building planning consent.

John Hall

John, on the subject of alterations to a listed building without gaining Listed Building Planning Permission the law is very clear. There are no time limits on the local Authority taking action and the onus will be on the owner (whether the existing or you!) to prove that the work was undertaken before listing. If the work on the property was done without permission you MUST get the conservation officer on to the site to discuss what you want to do and how to go about getting the approvals. The officer may take the view that they want to encourage you and hold off from taking action, but they may want to pursue the present owner for unauthorised work. If the latter is the case, keep clear until the dust has settled and any legal/planning matters have been resolved. Whatever you do, you must consult with the conservation officer, or you could find yourself in trouble and having to fight an action. If the owner refuses to let you bring an officer on site alarm bells should ring very loudly!

On the grant front a far more complex picture arises. Firstly, if you have a Grade I or Grade II* property you can apply for a grant under an English Heritage scheme. Secondly, although many local District Councils have small funds available for work on listed properties there is a train of thought which believes the price paid for any property should reflect its condition therefore the cost of any structural or other essentials works should be discounted from the property's market value. Obviously in a heated property market this is not the case as vendors bid for the cottage of their dreams regardless of condition and their ability to pay for as yet undefined work. Thirdly, even if your local district council has funds for grants each grant is discretionary and can change from year to year. Resulting in some undeserving cases being awarded money in one year simply because the funds are available and deserving cases receiving zero grants in another year because funds have run out. There is also a tendency that if you receive a small grant you will have to abide by any stipulations laid down by the council e.g. material type for thatch, as well as facing a possible penalty clause if you were to sell the property within a specified amount of time after the work has been completed. My advice would be to discuss things with the conservation officer concerning the alterations undertaken on the property then raise the issues of grants. If the response is reasonably favourable apply for a grant at the start of council's financial year when the funds are first made available.

SUBJECT: Leave it bare or give it a wash...limewash
FROM: Stephen Blake (Chipping Norton, Oxfordshire)
Malcolm, I am restoring a derelict outbuilding, substantially wrecked by previous owners. The open south aspect has a slate roof which will be supported by a green oak beam with upright green oak support in the centre - given that it is exposed to the elements, is any form of preservative required, or will the wood be robust enough to weather down naturally?

Stephen Blake

Stephen no form of preservative is required because Oak is robust enough to survive the outside elements and over time and will weather to a beautiful silvery grey hue. If you feel more secure with some form of surface treatment to keep the rain off of the wood as well as allowing any damp within the timber to evaporate simply limewash the oak. Because the oak is exposed please ensure you use a lime render on the wall. If sand and cement is used moisture will become trapped in the wall over time and may lead to the oak decaying around the margins where it comes into contact with the cement.

SUBJECT: Incorrect equipment leads to mis-diagnosis of damp
FROM: Michaela Rata (Norfolk)
We are purchasing a traditional Norfolk brick and flint cottage and have a report from a reputable local damp treatment company stating that the property has rising damp and recommending a chemical damp proof course. There is no apparent evidence of damp patches on the internal walls. The ground level immediately adjacent the property is some 1.5m higher and I wonder if this is causing penetrating damp. The Company also recommends tanking of a single storey element where the adjacent ground level on one side is approx. 1m higher abutting the building. I would be interested in your opinion.

Michaela Rata

Michaela, the likelihood is that the 'damp-proofing salesmen' who visited your home used an electrical conductance-type meter to diagnose rising damp. These meters do not really measure moisture they measure electrical conductance, and will give a reading on any building material which allows an electric current to flow through it. The meters are also calibrated for use on timber, and they can give reasonable approximations of moisture content in wood, but on materials such as flint and brick walls the reading they give are too high. For a more accurate reading the company in question should have used a calcium carbide meter , as well as test for ground salts in the plaster. If you have rising damp ground salts from the soil would be deposited in the fabric of your wall. For a more in-depth review of the damp-proofing industry visit the Jeff Howell's website on www.onthelevel.in-uk.com.

On a practical note I would adopt a wait and see approach allied with one or two practical suggestions. Firstly, ensure all of your property's guttering and downpipes are performing well and not leaking. Simply use a hose to pour water into the guttering to detect leaks or with the present poor weather conditions any problems should be self-evident. Secondly, has the original lime been raked out of the joints between the flints and replaced with cement. If this is the case the cement may allow rain or damp to penetrate the margins between the flints and the cement resulting in moisture being absorbed into the fabric of the wall and being unable to evaporate. Thirdly, you are quite to point out that the likely source of damp is due to high ground levels surrounding the property resulting in either penetrating damp or water simply draining to the lowest level, which in this case may be the base of your wall. Ideally, you should aim to remove the some of the soil in question until the floor level in your cottage is higher than the surrounding ground level. Once the soil is removed it may be advisable to run a French drain alongside the wall depending upon the depth of the property's foundations in a bid to direct surface water away from around the cottage. Dig an exploratory hole first to ensure that any French drain - perforated drainage pipe - if run alongside the house would not go below the level of the foundation. The same recommendations are applicable to the single storey building. Finally, if the soil in question is actually touching the wall it may be acting as a buttress to the wall thus preventing any movement. Therefore your surveyor should aim to pinpoint any structural problems e.g. removal of tie beams in the roof structure which may lead to wall spread and the possible movement of the wall in question.

SUBJECT: Beeswax & turpentine provide answer to parched beams
FROM: Louise Threapleton (Ripon, Yorkshire)
The beams in our 16 Cent cottage have been sandblasted. Some of the beams are still in reasonable condition, but some of the others look like parched aero bars! What oil or wax combination should I treat them with to put condition and a gleam on them, bearing in mind buffing wax would be difficult on such rough surfaces.

Louise Threapleton

Louise, you will need to following ingredients. Brown, unrefined beeswax, genuine pure turpentine, a wide mouthed jar and cheese grater. You should be able to obtain the beeswax from a local beekeeper and genuine turpentine is available from artist suppliers or some builders merchants.

The first step is to grate and fill the jar with beeswax until 75% fall when compacted. Pour in turpentine and shake. Because the beams you are dealing with are 'parched' and damaged aim to produce a fairly runny liquid. Screw lid on jar and leave in warm place for 1 to 2 days giving it a shake from time to time.

On parched and delicate worm eaten beams the polish should be runnier and gently applied with a brush, working it well into cracks and crevices. Once applied and left to dry it can be buffed with a soft brush.

SUBJECT: What lime mix for pointing flintwall
FROM: Andrew Pritchard (Fraxfield, Hampshire)
Thank you for your response. In answer to your question about the removal of the existing paint, I am scraping off the existing paintwork (a carefully as possible) and scraping out the joints. The paint comes off the flint work quite easily and a seems to clean up well with a stiff bristle brush. Thanks for your advice. One last question - I have heard of something called "compo" which is mixed with one of lime and one of cement but my local builder's merchant has never heard of it. Could you advise on a good "mix" for brick and flint?

Andrew Pritchard

Andrew, you have two choices in creating the correct lime mix for your brick and flint wall. Firstly, you should rake out some of the lime pointing and send it away for analysis. You will then receive an analysis providing you with the constituent parts of the mix for you to re-create. Alternatively, simply rake out some of the pointing and break it down until the lime, grit and sand particles are distinguishable. Then it is simply a case of obtaining the correct grade of grit and sand to mix into your lime putty. Crushed limestone can be used as the aggregate and if sea dredged sand is used it must be washed to ensure all salts are removed. On the ratio front use 1 of lime putty to 3 of sand & aggregate. Finally, try not to apply the material in amounts thicker than 10mm or in the full glare of the sun as the plaster will shrink causing cracking. It may also be worthwhile to attend a lime day at the Lime Centre in Winchester on 01962 713 636 or email him on bob@limecentre.co.uk.

SUBJECT: Limewash provides protection against erosion
FROM: Nikk Smith (Stockport, Cheshire)
Localised weathering of stone is apparent on the one corner of my converted Quaker Meeting House. The stone itself appears to be Limestone. I believe the weathering is due to the prevailing winds and the sheltering effect of other buildings on the construction. Is there any way to slow the process down, though?

Nikk Smith

If indeed your property is made from limestone simply apply limewash to the wall in question. The application of limewash will help to consolidate the surface and allow the wall to breathe. Simply reapply each year. Avoid at all costs the application of any form of liquid sealant which will lead to lasting damage to the fabric of the wall.

SUBJECT: Secret cleaning tips for brass knob
FROM: Patrick Hutchinson (Stockport, Cheshire)
We have an original front door dating back to about 1860 which we wish to restore. The door furniture on it appears to be original also, in particular a large, ornate, brass centre knob which has been painted many times over the years. We have removed all the paint with Klingstrip (Strippers paint removers), but have been left with a very dull and tarnished surface. Is there a product on the market, possibly a form of 'dip' which brass can be placed in to remove discoloration without the need for lengthy polishing? The design off the knob makes it very difficult to access the fine detail with supermarket metal cleaners. Any labour saving tips would be very appreciated.

Patrick Hutchinson

Well Patrick, there is no magic in the cleaning process. For a quick and comprehensive job, taking the knocker off and giving it to a local firm of metal finishers/ polishers would be a good idea for the first clean. Alternatively, I use either Brasso or (more often recently) Liberon's Brass Cleaner (for the initial go - it is more aggressive than is usual) then finish off with Liberon's Brass Polish. This again is easier with the knocker on a bench especially if it is a complex shape and needs ear buds to get at the crevices. Now come the special tips. Always wash the polished item with warm soapy water after polishing. This will remove the white scum that results from using Brasso (Liberon's stuff is much better) it also removes all traces of polishing chemicals from the surface. These actually accelerate tarnishing if left on. After washing apply a little beeswax furniture polish with fingers. This creates a thin film that keeps the atmosphere from the brass and further retards tarnishing. Advice provided by www.periodhouseshops.com.