Which Selleys flooring product do you need, and where does it sit in the system?

The Selleys flooring range is a trade range built around timber flooring installation, and the most useful thing to understand about it is that several of the products are not alternatives to each other — they are stages of the same system. A vapour barrier, a primer, a levelling compound and an adhesive each do a different job in sequence over a concrete slab, and skipping one because another sounds similar is how installations fail.

So the first question is not "which adhesive is strongest?" but "what is the subfloor, and what has to happen to it before the floor goes down?" Once the substrate is sorted, the adhesive choice follows from what you are sticking down.

What this category covers

This is one of the Selleys Trade categories — flooring products for trade professionals. The product listing on the live page loads dynamically, but the products beneath the flooring path can be confirmed from the site's own listing, and they fall into two clear groups: subfloor preparation (vapour barrier, primer, leveller) and flooring adhesives.

How to choose

Step one: is moisture coming up through the slab?

Selleys VBS Vapour Barrier is a highly cross-linked, two-pack epoxy moisture vapour barrier system. This is the product that addresses moisture rising out of a concrete substrate before a timber floor goes over it. Being two-pack means it is mixed before use and has a working life once mixed — plan the area you can cover accordingly.

Selleys VBS Rapid is the faster-turnaround member of the same VBS family. Note that the description published for it on the site refers to a heavy-duty bond and to a "Liquid Nails VBS Epoxy Kit" for metal and concrete, which does not match the flooring-system role its name and its position in this category imply. Treat that description with caution and check the product's own technical data before specifying it.

Step two: does the surface need bridging or levelling?

Selleys VP30 Primer is formulated for use as a bridging primer between Selleys VBS or VBS Rapid and self-levelling compound, as part of the Selleys timber flooring system. That is a precise role: it is what allows the levelling compound to bond over the cured epoxy barrier. If you have applied a VBS barrier and intend to level over it, this primer is the link between the two, not an optional extra.

Selleys SLC50 Leveller is a self-smoothing cementitious levelling underlayment specifically formulated for preparing concrete substrates prior to the installation of timber flooring. Self-smoothing means it finds its own level rather than needing to be trowelled flat, which is what makes it practical over larger areas.

Step three: choose the adhesive for what you are laying

Selleys Timberflex Timber Flooring Adhesive is the timber flooring adhesive in the range, described as giving a strong, flexible bond. Flexibility matters in a timber floor because the boards move with changes in humidity; an adhesive that holds but does not accommodate that movement transfers the stress somewhere less forgiving.

Selleys Direct Stick is a high-strength bond for timber, particleboard and MDF projects, described as suiting both DIY and construction work. Where Timberflex is named for timber flooring specifically, Direct Stick covers the wider set of sheet and board materials.

The products in this range

Product	Role
VBS Vapour Barrier	Highly cross-linked two-pack epoxy moisture vapour barrier system.
VBS Rapid	The rapid member of the VBS family; check its technical data, as its published description is inconsistent.
VP30 Primer	Bridging primer between VBS / VBS Rapid and self-levelling compound.
SLC50 Leveller	Self-smoothing cementitious levelling underlayment for concrete prior to timber flooring.
Timberflex Timber Flooring Adhesive	Strong, flexible bond for securing timber flooring.
Direct Stick	High-strength bond for timber, particleboard and MDF.

Related products elsewhere in the catalogue

• Selleys No More Gaps Timber Floors — for filling gaps around and between tongue and groove timber flooring, and between other timber panels and fittings. This is a finishing product for an installed floor, not part of the installation system.
• Selleys Araldite Extra Time Epoxy Adhesive — a longer working time epoxy for large surface areas or multi-assembly jobs, listed as suiting benchtops, flooring, coatings, structural application and load-bearing repairs.

The safety divide in this range — the widest in the Selleys catalogue

The page above treats these products as stages of one system, and that is the right way to plan a job. It is not the right way to plan your protection. Read as a hazard list rather than an installation sequence, this range splits three ways, and the gap between the ends of it is as wide as anything Selleys sells.

Group	Products	Classification
Danger — long-term health hazards	Direct Stick, SLC50 Leveller	Direct Stick: H334 (may cause asthma if inhaled), H351 (suspected of causing cancer), H373 (organ damage from repeated exposure), H332, H317, H315, H319. SLC50: H350 (may cause cancer — Category 1), H318 (serious eye damage), H315, H335
Danger — the two-pack hardeners	VBS Vapour Barrier hardener, VBS Rapid hardener	Vapour Barrier hardener: H314 (severe skin burns and eye damage), eye damage Category 1, H317, H302, H312 — Dangerous Goods Class 8, corrosive, UN 2735. VBS Rapid hardener: H318, H317, H315 — Dangerous Goods Class 9
Warning	VBS resins (both kits), VP30 Primer	Resins: H302, H319. VP30: H315, H319. No sensitisation, no carcinogenicity
Not classified	Timberflex Timber Flooring Adhesive	Not classified as hazardous. No signal word, no hazard statements, not Dangerous Goods

The single most useful fact on this page is that the two flooring adhesives are not equivalent on hazard, and the safer one is not the weaker one. Direct Stick is a moisture-cure polyurethane carrying respiratory sensitisation, suspected carcinogenicity and repeated-exposure organ toxicity. Timberflex is a silyl-modified polymer described as isocyanate-free and solvent-free, and it carries no classification at all. Where both are suitable for what you are laying, there is no protective argument for the polyurethane.

H334 is the statement to weigh. Respiratory sensitisation means the immune system can learn to react to the vapour, after which the reaction is generally permanent, is set off by concentrations far below the one that caused it, and gets worse each time. It is the mechanism behind occupational asthma in the trades that work with isocyanates. A flooring installer meets it in the worst possible setting — a whole room's worth of adhesive troweled out, curing and expanding, in a space with the windows shut because the floor is about to go down over it. If you are using Direct Stick, ventilate actively and wear an organic vapour respirator rather than a dust mask.

SLC50 Leveller is the hazard nobody expects, because it looks like a bag of cement. Its Category 1 carcinogenicity belongs to respirable crystalline silica — under 1% of the bag, but flagged as more than 0.1% respirable. Category 1 is reserved for agents where human carcinogenicity is established, not merely suspected. The entire exposure is in the dry powder: cutting the bag, tipping it, and mixing. Once it is wet there is no dust, and once it is cured the silica is locked in. Wear a P2 respirator for the two minutes that actually matter, and mix outside or with the bucket low.

On the two-pack kits, the resin and the hardener are not the same product. Both VBS kits pair a Warning-level resin with a Danger-level hardener, and the Vapour Barrier hardener is the more serious of the two: H314, severe skin burns, on a pouch that is between a third and two thirds isophorone diamine. Alkaline burns do not announce themselves the way acid does — there is often little immediate pain while the damage continues, so contamination gets left on the skin. Full gloves and goggles go on before the hardener pouch is opened, not after the two parts are mixed.

Comparing the flooring range on the numbers that decide the job

Three figures govern how a flooring day is planned: how far a pack goes, how long you have once it is open, and how long before the next trade can walk on it.

Product	Coverage	Working time	Walk-on / next stage
VBS Vapour Barrier	6 m² per litre; 3.6 L kit covers 20 m²	20–30 minutes once poured out	8–12 hours at 25°C; re-coat before 24 hours
VBS Rapid	40 m² per coat for engineered flooring; 20 m² for solid timber (per 5 L kit)	Under 40–45 minutes at 25°C	2–4 hours; re-coat before 72 hours
VP30 Primer	18–20 m² per litre non-porous, 10 m² porous; ~100 m² per 5 L pack	See product page	Overcoat at 30 minutes to 2 hours
SLC50 Leveller	~12 m² at 1 mm, ~4 m² at 3 mm per 20 kg bag	~15 minutes at 20°C	Walk on at 3–4 hours; floor coverings after 24 hours at 23°C
Timberflex	~20 m² per 10 L	See product page	See product page
Direct Stick	2 m² per litre — 20 m² per 10 L	See product page	Cures overnight; floors usually sanded the next day

The two adhesives cover the same ground from the same pack. Both are quoted at roughly 20 m² per 10 litres with the correct trowel. That closes off the argument that the unclassified adhesive must be the thinner or less economical one: on the published coverage they are level, and the difference between them is chemistry and hazard, not value.

The two VBS kits are a genuine trade-off, not an upgrade. VBS Rapid gets you back on the floor in 2–4 hours against 8–12 for the Vapour Barrier, and gives you 40–45 minutes of working time against 20–30. That is faster and more forgiving in both directions, which is unusual. What it costs is the re-coat window: VBS Rapid must be re-coated after curing and before 72 hours, while the Vapour Barrier's window closes at 24 hours. Plan the next stage against the shorter figure, because a missed re-coat window means mechanical preparation of a cured epoxy rather than simply rolling the next coat on.

SLC50's 15-minute working time is the tightest number in the range, and it does not scale. Fifteen minutes at 20°C, on a product mixed a 20 kg bag at a time and poured to find its own level, means the area you can cover is set by how fast you can mix consecutive bags rather than by the size of the room. Two people and two buckets is the usual answer; one person with one bucket produces a cold joint between pours. Note also that the figure is quoted at 20°C and the application range runs to 35°C — a hot slab shortens it further.

Coverage on the primer is the outlier worth checking before you order. VP30 goes twice as far on a non-porous surface as on a porous one, 18–20 m² per litre against 10. Over a cured VBS barrier, which is the role the page above gives it, you are on the generous end of that range.

Common questions about Selleys flooring products

Do I need all of these products, or just the adhesive?

It depends on the subfloor. The VBS barrier, VP30 primer and SLC50 leveller are subfloor preparation for concrete; the adhesive is what fixes the floor down. VP30 in particular exists specifically to bridge between the VBS barrier and a self-levelling compound.

What is the difference between Timberflex and Direct Stick?

Timberflex is named and described as a timber flooring adhesive giving a strong, flexible bond. Direct Stick is described more broadly as a high-strength bond for timber, particleboard and MDF projects.

When do I need VP30 Primer?

When you are putting a self-levelling compound over Selleys VBS or VBS Rapid. It is described as the bridging primer between those two layers as part of the Selleys timber flooring system.

What does self-smoothing mean on the SLC50 Leveller?

It means the compound flows out and finds its own level rather than being trowelled flat, which is what makes levelling a large concrete area practical.

Why is a vapour barrier necessary under timber?

VBS Vapour Barrier is described as a moisture vapour barrier system for concrete substrates. Concrete can pass moisture upward into a timber floor; the barrier is the layer that stops it.

What fills the gaps once the floor is down?

Selleys No More Gaps Timber Floors is designed for filling gaps around and between tongue and groove timber flooring, and between other timber panels and fittings.

Is this range for trade only?

Selleys presents flooring as one of its trade categories. Direct Stick is described as suiting both DIY and construction projects, so check the individual product page for the format and pack size you need.