RM3 · A12 / M25 J28 · 4 mi from Romford
Harold Hill Latex & Self-Levelling Compound Specialists
The standard we work to in RM3 is 3mm deviation over 2m — that's what modern engineered wood needs to lay flat over its lifetime. Beyond that, the floor moves as it settles, and the floating layer eventually opens joints or lifts at seams.
From £420 · Level survey £180 (refunded against booked work). Latex from £14/m², ply overlay from £22/m².
Typical turnaround: 1–3 days including cure time; larger areas 3–5 days.
What you're seeing in Harold Hill
Common signs we diagnose in RM3 subfloor levelling calls:
- Hollow-sounding spots when you tap the floor
- Doors dragging on the floor as it moves
- New flooring installer refusing to lay without prep — first sign the base is out of tolerance
- Visible dips or humps in the current floor's surface
- Skirting boards gapping at the top or bottom in specific rooms
What's actually happening
The likely root causes in Harold Hill's ex council homes and along A12 / M25 J28:
- 1
Chipboard sub-deck screws working loose over 20+ years
- 2
Wet-lay screed under UFH that wasn't fully cured before floor install
- 3
Extension floor poured at different height from the original
- 4
Concrete without DPM allowing moisture upward through the floor
- 5
Original screed poured out of tolerance and never levelled
Our repair process in Harold Hill
Step 1
Level survey
Straight-edge and laser survey across the whole area. We map high and low points, moisture-test the sub-deck, and give you a written spec of what needs doing.
Step 2
Fix loose or damaged sub-deck
Re-screw perimeter, replace damaged boards, packer under joists where levelling is required. Structural first, cosmetic second.
Step 3
Apply DPM if needed
For concrete without a moisture barrier we apply a two-coat epoxy DPM (Bona R540 + R580) or a bituminous membrane, depending on moisture readings.
Step 4
Latex self-levelling compound
Feather in dips with fibre-reinforced latex compound; pour a proper self-levelling layer where the deviation is large. Cures in 24 hours to a flooring-ready surface.
Step 5
Ply overlay where needed
For older sub-decks or where levelling depth would be excessive, we overlay with 5.5mm ply screwed at 150mm centres — the flooring industry standard for a stable base.
Materials & method
Exactly what we use on Harold Hill subfloor levelling jobs — no vague "trade-quality" waffle.
- Ardex A45 or Mapei Ultraplan latex self-levelling compound
- Bona R540 mist primer + R580 moisture barrier — for concrete DPM
- 5.5mm structural plywood BB grade — for sub-deck overlay
- Timbre Turbo-Drive 4x40 screws for perimeter and grid re-fixing
Timeline: 1–3 days including cure time; larger areas 3–5 days. · Price: from £420 · Level survey £180 (refunded against booked work). Latex from £14/m², ply overlay from £22/m².
Why Harold Hill clients pick us
- Straight-edge and laser levels on every visit
- Written spec of what we did, useful for future flooring warranties
- Straight-edge and laser levels on every visit
- Written spec of what we did, useful for future flooring warranties
Subfloor Levelling in Harold Hill — common questions
- How do you check my subfloor is dry enough?
- Pin and pinless moisture meter across the whole area, plus a calcium chloride test on concrete if we're unsure. Concrete needs 75%RH or below (Tramex reading) before wood or LVT goes on.
- How long does the latex take to dry before flooring can go on?
- 24 hours for foot traffic, 48 hours minimum before flooring is laid, 72 hours ideal. Wet compound under a moisture-sensitive floor is a recipe for a failure. We schedule around this.
- Can I DIY the levelling?
- For small feathering, sometimes yes. For anything over 5mm depth or requiring DPM or overlay, we'd recommend against it — the compound and prep skills matter, and re-doing it is more expensive than doing it right first time.
- Can I lay engineered wood on an uneven concrete floor?
- Only with proper preparation. Modern click-together engineered systems need 3mm/2m or better. Beyond that, the click joints stress, then fail. Latex first, floor after — no shortcut.
- Can you level over a chipboard sub-deck?
- Yes — but we usually re-screw the deck first (perimeter and joist centres), and if it's badly out of level we overlay with ply. Feathering latex directly onto chipboard rarely holds long-term.
- Do you cover Harold Hill for subfloor levelling?
- Yes — Harold Hill (RM3) is on our regular Romford route. We do subfloor prep for our own flooring installs and also for other flooring contractors in the area.
The straight answer for Harold Hill
Subfloor work is where reputations get made in flooring. Anyone can lay a plank on a flat base; getting the base flat, dry and stable is the actual skill. That's what we do all day in Harold Hill, and it's why our floors don't fail.
Get your Harold Hill subfloor levelled properly
Straight-edge survey, moisture test, written spec.
Nearby RM areas we cover
Not all combinations are live yet — where a nearby link 404s, the same team still covers that area.