Provide acoustic damping under an engineered wood floor | The Library

Why does an engineered wood flooring installation in a hotel bedroom need acoustic damping?
Wooden floors are often the preferred choice in hotel bedrooms to create an authentic and warm interior. If you select engineered wood flooring, however, you will need to think about acoustic isolation, so that footsteps in the room above cannot be heard in the room below. Effective acoustic insulation is a major consideration in construction or renovation work in hotels.

How do you achieve acoustic damping under an engineered wood floor? What underlay do you need?

A traditional underfloor acoustic system employs an acoustic membrane and an underlay and thus requires several stages of installation. Luckily, there is an easier installation solution available from Bostik that provides acoustic damping using an adhesive only. By installing engineered wood flooring straight onto our patented high-performance acoustic adhesive, you can achieve aesthetic quality and warmth without compromising on acoustics.

Bostik has the perfect three-part system for installing acoustically damped engineered wood flooring in a hotel room.

GRIP A500 MULTI is a universal solvent-free primer that prepares both porous and non-porous substrates by optimising grip for levelling compounds.
SL C740 FIBER MAXI is a fibre-reinforced, rapid, paintable self-levelling compound. It is suitable for use in both new-build and renovation projects and can be used in areas that are subject to moderate and high levels of foot traffic from 1 to 40mm in one coat.
WOOD H910 SILENTSTIK® is a patented high-performance acoustic adhesive for installing wooden flooring. The adhesive provides 19 decibels of soundproofing to the underside of the flooring. It is suitable for factory-varnished or unfinished solid wood floor elements up to 150 mm wide, all thicknesses, and factory-varnished engineered wood floors with a width greater than 90 mm.

Use these fit-for-purpose Bostik products to lay engineered wood flooring in hotel rooms.

How to lay acoustically damped engineered wood flooring.

Use the following three-part Bostik system to install an acoustically damped engineered floor in a hotel room. The second part, a self-levelling compound, will be required if your floor does not pass the relevant surface regularity requirements. (For example, some regulations stipulate that there must not be more than 3 millimetres of deviation under a 2-metre ruler or 1 millimetre under a 20-centimetre rule.) In case you need to level the floor, you will need the following:

Ensure the subfloor is sound, dry, clean of old residue, and free of cracks and laitance from previous work. The next step is to test the moisture level and ensure the readings are below 2%. Contact your local BOSTIK rep for installation details if the CM level is higher.

Once the subfloor has been secured, use BOSTIK GRIP A500 MULTI, a ready-to-use primer to prime the entire area. One 20kg container of GRIP A500 MULTI can cover around 200 m².

Use short-pile roller
One 25 kg bags of SL C740 FIBER MAXI self-levelling compound will cover around 5 m² when applied at 3mm thickness. (Mix 5-5.5 litres of water per 25kg bag; coverage 1.5 kg/mm/m²)
Electric drill and recommended mixing paddles (KR or DLX styles)
Stainless steel float
A WOOD H910 SILENTSTIK® notched trowel

How to lay acoustically damped engineered wood flooring step-by-step.

Step 1: Clean and prepare the substrate

Floors must be sound, free from laitance, cracks, and structural defects, and clean and free from dust, grease, curing compounds, sealers, or any other contaminants that may inhibit proper bond. The surface of the anhydrite screed should be sanded to eliminate traces of paints, mortars, plaster, and the surface layer of the screed.

Hard adhesive residues should be mechanically cut back to a minimum. Completely remove all soft and weak adhesive residues, paint, and gypsum residues. Measure the moisture content of the floor with a carbide bomb to ensure the adhesion of the glue. It must be less than 2.5% on a cement substrate and 0.5% on an anhydrite screed. If it exceeds 2.5%, the floor should be primed with a moisture vapour barrier coating before applying the self-levelling compound.

Step 2: Apply primer to the floor

Apply GRIP A500 MULTI primer evenly in a thin coat using a short-pile roller (coverage: 90 to 100 g/m² per coat). Do not over-apply, and avoid forming puddles. Allow to dry for 30 to 60 minutes prior to applying the self-levelling compound.

For anhydrite screed, apply undiluted primer (coverage: approx. 100 g/m²) and allow to dry for at least 24 hours before applying the self-levelling compound. Several subsequent layers may be necessary to completely impregnate the substrate.

Step 3: Prepare self-levelling compound for use

Pour 5-5.5 litres of cold, clean water (+8 to +25 degrees Celsius) into a clean mixing bucket. (Note: the addition of too much water may result in segregation of the compound.) Gradually add the bag of Bostik SL C740 FIBER MAXI to the water while continually mixing with an electric drill and recommended mixing paddle until a smooth lump-free mixture is formed.

After mixing, wait at least 30 seconds to allow the material to hydrate and expel the air created from the mixing to optimize the flowability of the SLC. Then remix for 30 seconds.

The self-levelling compound is now ready to be applied.

Step 4: Apply self-levelling compound

The self-levelling compound can be applied after the primer has dried (30–60 minutes, or 24 hours if the substrate is anhydrite screed). Once you have finished mixing the SL C740 POLYRAG, you will have 20 minutes of working time in which to apply it.

Pour the mixed material onto the prepared substrate. Using a stainless steel float, first spread the compound to zero to fill the pores, then smooth and spread regularly to the desired thickness (between 1mm and 40mm).

Step 5: Wait 24 hours

After about 3-4 hours, you will be able to walk on the levelling compound.

The curing time/installation time for wood flooring is 24-48 hours (at an ambient temperature of +23 degrees Celsius). Check the residual humidity of the substrate before installing wooden flooring.

Step 6: Store the floorboards in the room for at least 48 hours

Store the floorboards in the room they are to be installed at least 48-72 hours before laying so that they have the chance to acclimatise to the humidity of the air in the room.

Step 7: Apply adhesive and install the engineered wood flooring

Note: do not commence installation if the air humidity in the room is more than 65%.

WOOD H910 SILENTSTIK® adhesive must be applied with the special SILENTSTIK® notched trowel, which has been specifically designed to create adhesive ridges of the size and shape that will promote underfloor acoustic damping. The adhesive ridges must be formed so that they are continuous and oriented perpendicularly to the span of the floorboards.

Note: when the wear indicators (the thin line) on the trowel are no longer visible, the spatula should be changed to ensure the insulating performance of the adhesive continues to be achieved.

To ensure optimum contact between the adhesive and the wood, knock the floorboards with a mallet within 40 minutes of placing the adhesive.

The key benefits of Bostik’s system for installing acoustically damped wood flooring.

GRIP A500 MULTI:

Improves and provides bond strength of self-levelling compounds
Can be used on non-absorbent and absorbent surfaces
Odourless, ready to use
Application temperature range: +10 degrees to +25 degrees Celsius

SL C740 FIBER MAXI:

High versatility
Ideal for renovation
Perfect finish and self-levelling
Quick-drying
Paintable with a water-based product
Pumpable application
Suitable with all types of floorings
Application temperature range: +10 degrees to +25 degrees Celsius

WOOD H910 SILENTSTIK:

High acoustic performance (impact and airborne noise)
High mechanical properties
2 in 1: bonding and acoustic properties in one product
Suitable for underfloor heating
19 dB underfloor soundproofing

Achieve acoustic damping under engineered wood floors in hotels with confidence. Use GRIP A500 MULTI primer, SL C740 FIBER MAXI self-levelling compound, and WOOD H910 SILENTSTIK^® adhesive.

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