Substrates & Preparation
Edge Insulation and Perimeter Detailing for Liquid Screed
A compressible edge strip around the perimeter of a liquid screed floor allows for thermal movement and helps isolate the screed acoustically from the walls.
Around the edge of almost every liquid screed floor, a compressible perimeter strip separates the screed from the surrounding walls, columns and any upstands. This isn't a cosmetic detail — it accommodates the small amount of thermal and moisture-related movement that occurs as the screed cures and later as the floor heats and cools, particularly with underfloor heating.
Getting the detail right at doorways, thresholds and internal corners takes more thought than a straight run of wall, since these are the points where the strip is most likely to be omitted or compromised.
Why the screed needs to move independently of the walls
Liquid screed expands and contracts slightly with temperature, and without a compressible gap at the perimeter, that movement would push directly against the surrounding walls, potentially causing cracking either in the screed itself or at the wall-floor junction. The edge strip absorbs this movement invisibly, doing its job simply by being compressible and continuous around the whole floor perimeter.
Doorways and awkward junctions
A straight wall run is the easy part — thresholds, door linings, and internal corners are where perimeter strip is most often forgotten or cut too short during a busy installation. Carrying the isolation detail consistently through these junctions, and making sure it isn't bridged by debris or accidentally bonded to the screed, matters as much as getting the main wall runs right.
Edge Insulation & Perimeters — the points that decide it
- Perimeter edge strip is typically a compressible foam or similar material fixed to walls before the screed is poured
- It accommodates thermal movement in the screed, particularly important where underfloor heating causes cyclical expansion and contraction
- The strip also helps limit flanking sound transmission between the floor and adjoining walls in acoustic-sensitive builds
- Doorway thresholds need the perimeter detail carried through carefully, since these are common points where the strip gets missed or cut short
- The strip is usually trimmed back after the floor finish is installed, leaving a small movement gap concealed by skirting or a threshold trim
- Columns, internal partitions and any other vertical elements meeting the floor need the same edge isolation as external walls
Checking your floor's perimeter detailing before we pour?
We'll fit and check edge insulation around your whole floor, including doorways and awkward junctions, before the screed goes down.
Or call our landline on 01392 237700
Edge Insulation & Perimeters — your questions
In short
A compressible edge strip around the perimeter of a liquid screed floor allows for thermal movement and helps isolate the screed acoustically from the walls.
Checking your floor's perimeter detailing before we pour?
We'll fit and check edge insulation around your whole floor, including doorways and awkward junctions, before the screed goes down.