Different Polyurethane Floor Finishes
After sanding, timber floors can be finished in various ways creating a more matte or polished look, and a more-or-less durable surface. Which finish you choose depends on the visual effect you are after, and the maintenance you are prepared for. One popular finish is polyurethane, which can be either water or solvent-based.
Water-based polyurethanes are manufactured in a wide range of sub-categories, including resin and acrylic blends. Different formulations produce different degrees of hardness of finish, ranging from low to high durability. Unlike oils or waxes which typically penetrate timber, strengthening the wood itself, a polyurethane finish protects flooring by forming a hard shell across the top.
An advantage of water-based polyurethanes is that they provide excellent resistance to edge bonding. Edge bonding is when a coating seeps between boards, bonding them together; this doesn't allow for the natural contraction and expansion of the floorboards. In turn, these inflexible bonded boards can force noticeable gaps to appear in other areas of the flooring.
While water-based polyurethanes can darken timber, they don't yellow it to the degree that a solvent-based formulation can. Also, because the plastic polymers in the mix are combined with water rather than a solvent, it is a greener option than a solvent-based product.
A Solvent-based polyurethane finish provides the hardest wearing and most durable option: available in high gloss and matte. Usually, several coats are needed to fully seal a timber floor with a plastic-like coating. Each subsequent layer creates another hardened film on top of the previous. While solvent-based polyurethane is extremely hard wearing, it can bond the edges of floorboards together, creating an edge bonding problem. Also, because solvent-based polyurethanes emit a strong odour, both when applying and drying, masks and protective gear are required during the application process.
Both water and solvent-based polyurethanes cannot be reapplied directly over a previous finish, but rather the area needs resanding first, so this makes spot-fixing difficult. Natural oils and wax type finishes, in contrast, can be reapplied to timber flooring without prior sanding.
When choosing a finish for your timber floors, you need to consider the look you want, whether more matte or shiny and also the durability of the finish. A more durable finish will generally translate into less frequent reapplication. Another consideration to bear in mind is the fumes emitted when applying and drying.
For more information, contact your local flooring service today.