Timber Treatment
Timber Treatment in the UK
Introduction
Our traditional building methods combined with a predominantly damp, temperate climate causes the UK housing stock to suffer some of the highest levels of risk from insect and fungal attack to structural timbers. It is, therefore, considered 'good practice' in building design to pre-treat timber with preservatives as a lifetime precaution against dry rot or woodworm (e.g. NHBC standards).
Unfortunately, most traditional buildings (and a lot of relatively modern ones too) do not have the benefit of such protection and this, combined with poor maintenance, leads to many cases of timber decay being identified during housing surveys. If you suspect that such problems may exist in your property an AAWU member would be able to identify the precise type of insect and/or fungal damage and recommend a repair strategy in line with industry codes of practice.
If a preservative treatment is recommended you can be sure an AAWU member will use only the safest and most effective products available in the remedial industry. All products are Approved by the HSE under The Control of Pesticides Regulations 1986 and are generally of low hazard/low environmental impact using low-solvent technology. All wood preservative products are listed by English nature as 'safe for use' where bats are roosting.
Timber Treatment
These brief descriptions of common timber decay species may help you to ascertain whether you have a problem which requires further attention. However, the list is not exhaustive so we recommend you contact your nearest AAWU member for further advice and a full survey.
Timber Decay Diagnosis Guide
| Insect | Identification Characteristics | Treatment* |
|---|---|---|
| Anobium punctatum Common Furniture Beetle |
Flight holes: Approx. 1.5 mm Diam Bore dust: Gritty (fine sand) lemon shaped pellets. Predominantly found in softwoods although sapwood of hardwoods may also be affected, especially in damp conditions. |
Standard woodworm specification, (surface spray) and paste or gel applications as necessary. |
| Xestobium rufovillosum Death Watch Beetle |
Flight holes: Approx. 3.0 mm Diam Bore dust: Like coarse sand. Bun shaped pellets. Normally in oak, associated with damp timber and fungal decay. |
Standard woodworm specification (surface spray) and paste or gel applications as necessary. Consider supplementary treatments to larger beams. |
| Hylotrupes bajulus* House Longhorn Beetle |
Flight holes: Oval, 6-9 mm Diam Bore dust: Contains cylindrical pellets. Affects softwoods only, generally restricted to Surrey (Camberley Beetle). |
Standard woodworm specification (surface spray) and paste or gel applications as necessary. Consider supplementary treatments to larger beams. |
*Detailed recommendation should always be sought from an AAWU member - these notes are for guidance only
| Fungi | Identification & Characteristics | Remarks | Treatment* |
|---|---|---|---|
| Donkioporia expansa White Rot Wet Rot |
Fruit bodies: Thick, hard plate or bracket. Dull fawn or biscuit colour. Long pores, often in several layers. Mycelium: White to biscuit in colour found within the timber. |
Attacks hardwood, mainly oak. Will decay softwood if adjacent. Wood reduced to consistency of whitish tint. No cuboidal cracking. | Standard wet rot specification (remove decayed wood, re-instate using fungicides as required). |
| Coniophora puteana Brown Rot Wet Rot Cellar fungus |
Fruit bodies: Thin plate. Greenish olive brown. Spores on many minute pimples. Rarely seen. Mycelium: Slender, thread-like, first yellowish, soon becoming deep brown or nearly black |
Causes darkening of the wood. Small cuboidal cracking usually hidden below a sound veneer which appears to be stained with water. Attacks wood in a very damp situation in cellars, skirting boards etc. | Standard wet rot specification (remove decayed wood, re-instate using fungicides as required). |
| Fibroporia vaillantii Brown Rot Wet Rot 'Poria' |
Fruit bodies: Soft, white plate, hard when dry. Spore bearing surface showing numerous minute pores. Mycelium: Very white fern-like growth on edges of sheet, never showing colouration. Strands remaining flexible when dried |
Causes darkening of the wood. Large cuboidal cracking. Often found under floor covering. | Standard wet rot specification (remove decayed wood, re-instate using fungicides as required). |
| Serpula lacrymans Brown Rot Dry Rot |
Fruit bodies: Fleshy, soft plate. Spore bearing surface yellow to red, with wide pores or labyrithine ridges and furrows. Edges white. Mycelium: Soft, white/grey sheets or cushions showing patches of yellow and tinges of lilac. Strands sometimes pencil-thick (become brittle when dried). |
Causes darkening of the wood. Large cuboidal cracking. Cubes same size or larger than those of Fibroporia vaillantii. |
Standard wet rot specification (remove decayed wood, re-instate using fungicides as required). Trace the growth of mycelium behind plasters and/or concrete - sterilise masonry as required. |
*Detailed recommendation should always be sought from an AAWU member - these notes are for guidance only