The Nitty Gritty Of Maintaining Wooden Floors
An expert viewpoint from the timber floor specialist at BM TRADA, the organisation that provides independent certification, testing, inspection, training and technical services
Peter Kaczmar, wood floor specialist at BM TRADA, discusses maintenance options to keep timber flooring looking as good as the day it was installed:
YOU don’t have to be a Time Team fanatic to realise that timber has been used as a flooring material for centuries. Its combination of flexibility, sustainability and aesthetics has pushed it up the shortlist of materials in architects and specifiers’ minds: in fact, it is increasingly becoming the number one choice for both residential and commercial situations.
It’s hardly surprising, given the choice on offer. A variety of wood species of different colour and figure are available and styles range from simple rustic planking to the elaborate and formal inlaid floor. And, when it comes to appearance, it’s no surprise that the beauty of wood flooring is a major selling point.
As with all things, however, there comes a time when as a result of in-service wear or surface damage the appearance of the floor will need to be restored through a programme of remedial measures.
Most flooring is currently sold pre-finished with a factory applied lacquer, which sooner or later will become damaged to the point where remedial maintenance will be required.
If the damage is superficial, it will generally be possible to achieve a good surface quality by light rotary abrasion using a screen meshing procedure which removes little or no wood from the surface. This is followed by the application of the required number of maintenance coats of lacquer. It is usual to do this several times before more substantial maintenance is carried out using more aggressive abrasion procedures.
Where more severe surface damage has been sustained, such as deep scratches or indentations, it will be necessary to adopt a more aggressive approach and to remove the surface layers of wood using a belt or drum sander fitted with successively finer grades of abrasive papers.
Such operations generally consist of three or more consecutive abrasion cycles starting with a course grit (P40-60) gradually reducing to P100 or less. The disadvantage of this as a remedial process is that successive remedial cycles will reduce the overall thickness of the wear layer in the case of engineered boards.
Engineered boards cannot be sanded down to the core layer and manufacturers always allow for about 1-1.5mm of the hardwood layer to remain after which no further sanding operations may be carried out.
The European Standards guidance for most types of wood flooring stipulate that the flooring elements should be capable of undergoing renovation at least twice. Commonly, the hardwood wear layer is 3.4mm in thickness, meaning that approximately 2mm can be removed before the floor is replaced.
Under normal circumstances, therefore, approximately four remedial maintenance cycles can be carried out for a typical wear layer of 3.4mm, working on the principal that each abrasion cycle will remove up to 0.5mm of wood from the surface.
Newly abraded floors can be sealed with a surface lacquer or impregnating oil. Lacquers deposit a layer of resin onto the surface which provides the main protective component.
In contrast, oils are impregnating in nature and do not normally form a surface layer, but work mainly by improving resistance to water-uptake and dirt pick-up by the wood surface.
Oils provide much less long-term protection to the floor surface, but offer the advantage of allowing frequent spot repairs to be carried out. In heavily trafficked commercial environments where certain areas are subjected to high footfall (eg tops of escalators) oils can provide a useful and easy solution to the problem of localised wear in trafficking hot-spots.
In contrast, lacquers provide much longer-lived solutions, although spot repairs cannot usually be carried out seamlessly and require closing down the entire area of the floor whilst maintenance is carried out.
Developments in the formulation of flooring lacquers have resulted in a bewildering array of products ranging in formulation from conventional oleo-resinous products to acid-catalysed melamines and more recently water-borne alternatives such as PU-acrylate copolymers and 1 & 2 pack polyurethanes.
These differ substantially in their relative wearing, curing and appearance characteristics. When re-finishing previously finished floors, care should be taken to ensure product compatibility. Consideration should also be given to the possibility of residual contamination in the form of fallout from abrasion cycles, which can settle out as dust on floor surfaces and interfere with adhesion properties.
Sealers should be allowed ample time to cure before subjecting them to trafficking. This can take several days to a week depending on the formulation of the lacquer.
During in-service use, the floor should be regularly swept and kept clean of surface grit and other debris. The floor should be cleaned at least every fortnight with a mild detergent and a regime of maintenance with polishes and surface dressings should be specified as an integral part of the seal specification as a measure extending its lifespan.
One of the most common causes of premature failure of floor seals is the lack of adequate entrance or barrier matting. Coarse matting should be provided at the entrances of halls etc and regularly cleaned.
Floor mats trap grit particles which would otherwise scour the floor surface. Similarly, furniture legs in contact with floor surfaces should be protected with felt, cork or textile pads. Rubber pads are not recommended as some may leave indelible marks.
Observation of the above basic principals will serve to extend the lifespan of a wood floor and help to extend both its useful service life and its original attractive appearance.
Wood Flooring – A professionals’ guide to installation by Peter Kaczmar is available to buy from http://bookshop.bmtrada.com
T: 01494 569700
This article has been reproduced from the Contract Flooring Journal website. You can find them at www.contractflooringjournal.co.uk.