Think twice before you place anything against the external walls of your house. Past owners of this property didn't; and the present ones had to pay the price! 

hat had seemed a good idea twenty years ago - to build a raised area for a garden seat - had potentially disastrous consequences when dampness, striking through the lower reaches of the wall, instigated a rather nice outbreak of dry-rot.  Why do these things always seem to show up just as you're trying to sell the house!

Property:   Skipton

Instructions Instructions were received by telephone to inspect the property and report on an outbreak of fungus in a window seat in the downstairs sitting room.

Background The client is in the process of selling the property and does not presently reside at the address. A recently noticed smell of mushrooms alerted her to the fungus.

Disclosures I have no affiliation, financial or otherwise, with the client or the property.

Limitations Limited to the above.

Restrictions Nil

Date of Survey Juy 2005

Weather Fine, hot and humid.

Viewing Orientation All observations are made as if looking towards the house from the front.

Type of Property A mid terraced property, probably Georgian and built of stone beneath a stone slate roof. The property is set slightly below the carriageway and has ground floor kitchen and sitting room. It does not have double-glazing but there is gas fired central heating.

External Observations The property faces in southerly direction and the main issue concerning this report is the level of the garden immediately in front of the property. At some time within the last twenty years or so the level has been raised and a sitting out area has been created. This alteration has resulted in the ground level immediately to the front of the property being at least nine inches above the internal floor level, whereas prior to this, it was approximately level or slightly below.
The area created has been filled with gravel and the drainage inspection chambers have been raised to accommodate the change.

Internal Observations Visual evidence of a problem was in the form of a fruiting body of the fungus Serpula Lacrymans, colloquially known as ‘dry rot’ on the underside corner edge of a wooden window seat and also on the cushion that resided on top of it.

The window seat itself is directly beneath the front windows of the property and adjacent to the raised garden section mentioned in ‘External Observations’. It was made of softwood planking topped with plywood sections.

Moisture meter readings were taken and although the majority of them indicated a moisture content (MC) of less than 20%, some were much higher than this in localised areas.

The central heating radiator was removed and the window seat was broken up and placed outside. There was ample evidence of dry rot on the timbers of the seat in the form of mycelium growth and strands. Cuboidal rot was also apparent in some of the softwood members.

MC was tested in adjacent timbers and also those in other areas of the room. None of these had a MC that would allow rot to instigate or prosper, the majority being beneath 15%.

Meter readings of localised areas of the wall beneath the window indicated that it was very damp.

The area beneath the stairs was checked and the wall on the opposite side to the garden store was also found to be damp. Condensation will account for a large percentage of this moisture. Also, softwood timbers that support the stairs have suffered from an attack of woodworm (Anobium Punctatum). I could not see any signs of frass or other ongoing insect activity and I concluded this attack was now extinct.

Discussion This attack of dry rot was confined to the window seat and was caused by dampness striking through the front wall of the property. This itself was possible because of the high ground level created by the alteration to the garden. Given the spread of the rot I would estimate that it commenced approximately three years ago and this may have coincided with the extreme rain and flooding that occurred in this part of the town during that time.

Dry rot is no different to any other timber fungus in that it requires both food and moisture in order to survive. The primary cure for this (and any other) rot is to remove the moisture and the rot will then perish. Secondary cures are very often unnecessary.

I think this particular outbreak was already in some difficulty - probably due to an ever-decreasing lack of nutrient - because it was beginning to produce fruiting bodies. These are often an attempt at ongoing propagation when the fungus needs to seek a new, more suitable, environment

Conclusions Removal of the affected timber and general cleaning up has been carried out by myself. You should destroy the affected timber.

Adjacent to the front wall, and along its entire length, construct a trench to the depth of the level prior to the alteration. It would be better to remove the entire raised area if this is possible, but if not, a trench, nine inches in width and lined with slate along its bottom and outer wall, would be acceptable. This trench must be kept clear of garden rubbish, especially that which can compost. You may wish to consider a form of cast iron grating over the top of it to assist with this chore.

On the inside of the property you should hack off the remaining rendering and replace it in its entirety to a level just below the slate protrusion with a sand and cement mix in the ratio of 4:1 sharp sand to cement. A waterproofing agent, such as Febproof, should also be added to the mix in accordance with the manufacturer’s instructions. The alkaline content of the render mix will kill off any remains of the organism.

Re-build the window seat using pre-treated timbers only. This is very important. However, it will probably rule out the use of sheet materials, such as plywood, and the design may therefore have to be slightly different.

In the base of the window seat, introduce ventilation in the form of ‘hit and miss’ grills. Space these grills no further than 1 metre apart. Replicate them on the top of the seat adjacent to the front wall.

Other than the above, no work is required.

I trust the above is satisfactory for your purposes but if you require further clarification please do not hesitate to contact me.

Surveyor Patrick F Doyle CSRT M. Inst. R.T.S.

Qualifications Certificated Surveyor in Remedial Treatments issued by the BWPDA.

Date of Report July 2005

Signed Surveyor

The above findings are based partly on the interpretation of results from a standard non-destructive inspection; this, by necessity, has limitations. If you require confirmatory/definitive diagnosis of my findings then this can be undertaken by the use of destructive methods of investigation: these will involve some damage and costs.