If the screed is even, strong and dry enough, then only mechanical surface preparation such as grinding and cleaning is required, before wood floor bonding is possible. However there are many situations where the existing or even new screeds are not suitable, and additional treatment is necessary before wood flooring can be installed. Sika has developed complete balanced system solutions for all of the different possibilities that may be found in these situations.
Screed Issues:
Out of level and uneven
Solution
With local patching and levelling compounds the floor is brought to the required tolerances. Strong and durable adhesion between the substrate or screed and the patching or levelling materials is given by a primer where necessary.
Sika products
Sikafloor® Patch
Sikafloor® Level
Sika® Screed
Cracks
Solution
Cracks in the surface must be filled and sealed appropriately. Therefore generally they need to be widened / opened at the surface to get sufficiently strong flanks for bonding the most suitable filling and sealing material, according to the dimensions and nature of the crack.
Sika products
Sika® Primer MB
Sikadur®-31
SikaBond®-850
Anchorfix-3+ / 3001
Insufficient surface strength
Solution
The screed surface must be sufficiently strong enough to give adequate results during the surface testing procedures, as previously referred to. Should the surface not meet these requirements, then surface strengthening is required.
Sika products
Sika® Primer MB
Sika® Primer MR Fast
Moisture content
Solution
Dependent on the moisture content of the floor, alternative different moisture barrier systems can be applied. Accurate measurement of the screed moisture content is essential before making the right system/product selection. Important Note: Calcium sulphate based gypsum and anhydrite or alpha – hemihydrate screeds will disintegrate if excess moisture is trapped in them by application of a moisture barrier.
Floor slabs without a damp proof membrane and subject to rising moisture also need special treatment. As a global leader in structural waterproofing, Sika always has a suitable solution for every eventuality.
Sika products
Sika® Primer MB
Sika® Primer MR Fast
Acoustic requirements
Solution
Sound and noise limiting regulations within each room and for any adjacent rooms and areas, can require specific sound dampening systems in the build-up of a wood floor. The best solution has to be determined individually according to the type of subfloor, the screed and the wood floor that is required. There are country specific standards developed specifically for this requirement, such as NF DTU 51.2 article 4 in France for example.
Sika has simple and efficient systems to allow your wood flooring to easily comply with all of these regulations.
Sika products
Typically Sika® AcouBond®-Systems
Existing floors, special situations and other complex requirements or circumstances
Solution
Thorough evaluation and preparation is often needed before a new wood floor can be installed in order to avoid problems. Typical situations are:
Existing floors with residual adhesive:
- Poor adhesion and incompatibility between the existing residues and the new adhesive
Wooden floor boards or other dry floor substructures:
- Inadequate fixing of the boards or elements
- Uneven subfloors
Tiled or stone floors:
- Low bond strength of the existing tiles to the floor
- Poor adhesion of the new wood floor adhesive due to residual cleaning agents or oils
Existing resin floors and mastic asphalt surfaces:
- Poor adhesion and incompatibility with the new
Sika products
Many different Sika advice or system solutions to overcome each specific problem.
Author
Dr. David Sager
Corporate Market Development Manager
Target Market Sealing & Bonding
Sika Services AG