LVT Flooring Installation: Glue-Down vs Click, Subfloor Flatness & Expansion Gaps

Quick Answer: Luxury Vinyl Tile (LVT) installation requires a flat subfloor — within 3mm per 1.8m (2mm per 1m for glue-down). Glue-down LVT is more stable and suitable for UFH; click LVT is faster to install and can be floated without adhesive. Both types require minimum 24-hour acclimatisation at 18–22°C. Expansion gaps of 5–8mm at all fixed objects are required for click LVT; glue-down requires no perimeter expansion gap but needs movement joints in large rooms.

Summary

LVT (Luxury Vinyl Tile) has become the dominant hard floor choice in UK domestic and commercial refurbishment in the past decade. Its water resistance, durability, and ease of maintenance have made it the go-to alternative to ceramic tile in kitchens, bathrooms, and open-plan living areas. However, LVT is also one of the most frequently failed floor finishes — not because of product quality, but because of incorrect installation.

The two most common failures are: (1) subfloor not flat enough, causing the LVT to crack at grout lines or flex along joins; and (2) insufficient expansion allowance in click LVT, causing the floor to buckle in warm weather. Both failures are installer errors. LVT is unforgiving of a bad subfloor in a way that carpet is not.

UK manufacturers and the Contract Flooring Association publish detailed installation guides that cover substrate requirements, adhesive selection, and movement joint spacing. These should be the reference for any LVT installation.

Key Facts

• Subfloor flatness — glue-down — Maximum 2mm per 1m (BS 8203)
• Subfloor flatness — click/floating — Maximum 3mm per 1.8m
• Subfloor moisture — Must be below 75% RH (test with hygrometer per BS 8203)
• Acclimatisation — Minimum 24 hours at room temperature (18–22°C). Some manufacturers specify 48 hours
• Glue-down adhesive — Pressure-sensitive adhesive (PSA), hard-set adhesive, or modified adhesives depending on product. Always use manufacturer-approved adhesive
• Trowel notch for glue-down — Typically V-notch 1.5mm × 1.5mm or as specified. Using the wrong notch results in insufficient or excessive adhesive
• Click LVT expansion gap — Minimum 5mm at all walls and fixed objects (door frames, cabinets, pipes)
• Glue-down movement joint — Required at doorways and at approximately 15m in any direction (or follow manufacturer's guidance)
• Underlay for click LVT — Many click LVTs have an integral backing. Do not add additional underlay unless manufacturer specifies — double underlay causes instability
• UFH compatibility — Most LVT is suitable to 27°C floor temperature. Glue-down preferred for UFH as click systems can expand and contract with heat cycles
• Subfloor over concrete — DPM must be present or moisture membrane applied. Anhydrite screed requires primer before adhesive
• Old adhesive on substrate — Remove or encapsulate, never lay over bitumen (plasticiser migration). Use appropriate levelling compound

Quick Reference Table

Detailed Guidance

Subfloor Assessment

Concrete and screed: Use a feeler gauge or straightedge to check flatness. Grind down high points — do not just fill over them. Fill depressions and trowel marks with self-levelling compound (SLC). Allow compound to cure per instructions (typically 2–24 hours depending on depth). Test moisture — this is non-negotiable.

Timber subfloors: Floorboards are not an acceptable substrate for LVT without a ply overlay. Individual boards flex differently and the edges telegraph through the LVT as a ridge. Overlay with 6mm or 9mm exterior-grade plywood (not OSB — OSB swells with humidity). Screw at 150mm centres throughout and 50mm from edges. Ensure all screws are flush or just below surface. Use a belt sander or angle grinder to knock down any high joints. Then check flatness.

Anhydrite/calcium sulphate screed: Must be sanded to remove laitance (the hard crystalline surface layer). Prime with manufacturer-specified primer before adhesive — cementitious adhesives do not bond to unprimed anhydrite.

Existing vinyl or LVT: Usually can lay on top provided it is fully adhered, not brittle or cracked, and level. Apply SLC skim coat to eliminate any surface texture. Check the existing material is not thermoplastic asbestos tile (pre-1980 grey/black tiles) — these must not be disturbed without asbestos survey.

Acclimatisation

Store LVT boxes flat (not on edge) in the room where they will be installed, at the room's normal operating temperature, for minimum 24 hours before installation. Do not lay LVT brought straight from a cold van — it will contract when it warms to room temperature, opening up joints.

Laying Pattern Planning

Plan the layout before cutting. Draw the room on paper and mark the centre of the room. Work from the centre outwards to give balanced border tiles at each side. Avoid narrow cuts (less than half a tile width) at doorways and in prominent sightlines. Plan which direction the planks will run — typically parallel to the longest wall or parallel to natural light.

Glue-Down Installation

1. Test spread adhesive on a small area and allow to become touch-dry (tack). Timing varies by product and temperature — follow manufacturer's pot life guidance
2. Apply adhesive with specified notched trowel, working in manageable sections (typically 3–4m²)
3. Allow adhesive to reach correct tack (manufacturer specified — often 15–30 minutes). Test: press fingertip — adhesive should string and be tacky but not transfer to skin
4. Press LVT tiles into adhesive with firm hand pressure. Use a roller (50–75kg floor roller) over the entire area within 30 minutes of laying
5. Butt joins tightly — no gap at joins on glue-down LVT
6. Wipe off adhesive from surface immediately with damp cloth. Dried adhesive is very difficult to remove
7. Protect from foot traffic for minimum 24 hours

Click LVT (Floating) Installation

1. Lay first row along the starting wall (usually the wall opposite the door). Use spacers to maintain expansion gap
2. Click subsequent planks into the long side first (horizontal click), then into the end join (vertical click). Listen for a positive 'click' — if it doesn't click, the join is not secure
3. Use a tapping block and mallet for end joins — never strike the LVT surface directly
4. Stagger end joins by minimum one-third of plank length in each row
5. At doorways and fixed objects, maintain minimum 5mm expansion gap and cover with appropriate threshold bar or beading

Cutting: Score and snap for straight cuts on most LVT. Use a jigsaw or utility knife for curves around pipes and architraves. Mark pipe holes oversized (15mm diameter for a 22mm pipe) and cover with collar.

Finishing

Silicone or colour-matched sealant at the junction with skirting boards covers the expansion gap neatly. Do not use rigid caulk — it will crack when the floor moves. Scotia beading pinned to the skirting (not the floor) is the traditional finish.

At doorways, fit the appropriate threshold bar: T-bar for carpet-to-LVT, reducer for height differences, or square-edge profile where both floors are at the same height.

Frequently Asked Questions

Can LVT go in a wet room or shower area?

The LVT itself is waterproof, but the joins between tiles/planks are not fully watertight. In wet rooms (shower areas where water floods the floor), grout-free click LVT is not appropriate — use ceramic tile with fully waterproof adhesive and grout, or a specialist wet room vinyl welded at the joins. In bathrooms with a shower enclosure where the LVT is not under the shower, glue-down LVT is fine.

My click LVT is lifting/buckling. What went wrong?

Almost certainly an insufficient expansion gap or a join with a fixed object (door frame, kitchen unit plinth) that was installed tight. Click LVT expands significantly with heat — a 5m floor run can expand by 10mm at 30°C. Remove the skirting or beading and cut 5–8mm from the nearest plank edges to create the required gap.

Can I lay LVT over underfloor heating?

Yes, but check the product specification. Most LVT is rated to a maximum floor surface temperature of 27°C. UFH setpoint must keep floor surface below this. Glue-down LVT is better over UFH as it cannot lift and buckle. Commission UFH for at least 7 days before laying to stabilise screed moisture content.

What is the difference between LVT and vinyl sheet?

Both are vinyl products, but LVT (Luxury Vinyl Tile or Plank) is typically 2–6mm thick, rigid (or semi-rigid), and installed as individual tiles or planks. Sheet vinyl (cushion vinyl or vinyl sheet) is a thin roll product, typically 2–3.5mm, fully flexible, and laid in one piece. LVT gives a better simulation of tile or wood. Sheet vinyl is better for wet rooms and areas where water resistance is critical, as there are no joins.

Regulations & Standards

• BS 8203:2017 — Code of practice for installation of resilient floor coverings (the primary standard for LVT installation)

• EN 649/EN 654 — LVT product standards covering wear classification

• Approved Document C — Ground floor moisture resistance requirements

• CFA Technical Bulletin TB022 — LVT installation guidance

• Contract Flooring Association Guidance — BS 8203 guidance and installer standards

• Amtico Installation Guide — Detailed glue-down LVT installation specification

• Karndean Technical Guide — Click and glue-down installation specifications

• screed types — Screed substrate preparation for LVT

• flooring types — LVT compared to engineered wood and laminate

• underfloor heating tiles — UFH commissioning before floor finishes

• screed depth — Screed depth and volume reference