Point-load specification
Specifying liquid screed for point loads and racking
Concentrated point loads need specific attention in a screed specification, since a floor that copes with general foot traffic can still fail locally under a racking leg.
Planning racking or heavy equipment on a new floor?
Let us know the loads involved before the screed is specified so depth and strength class can be checked.
Or call our landline on 01392 237700
General strength class and depth figures are usually set with distributed loading in mind, but concentrated point loads such as racking legs, machine feet or storage unit bases behave differently and can create local stress well above the floor's average design load.
Where these loads are known at design stage, the specification should address them directly rather than relying on the general floor build-up to cope.
Because a racking leg can concentrate more stress on a small footprint than a car parked across a whole bay, the specification should record actual leg loads from the equipment supplier rather than a generic commercial assumption.
Point loads and racking — the points that decide it
- Racking leg loads should be identified with actual figures from the racking supplier wherever possible, rather than estimated.
- Load-spreading plates or pads beneath racking legs can help distribute a point load over a larger screed area.
- Locally increased depth or a higher strength class may be needed under known point-load locations, agreed with the designer in advance.
- Floating build-ups need particular attention for point loads, since the insulation beneath can compress unevenly under concentrated weight.
- Racking layouts sometimes change after the floor is finished, so specifying a reasonable margin for likely future loads is worth considering at design stage.
Why average design load isn't the whole picture
A floor specified for a certain distributed load in kN/m² can still see localised stresses that exceed the underlying screed's capacity if a heavy point load lands on a small footprint. This is why racking and machinery locations should be flagged individually rather than assumed to be covered by the general specification.
Working with the racking or equipment supplier
Getting actual leg-load figures from the racking or equipment supplier, rather than a generic assumption, allows the screed depth and strength class to be checked properly against the real loading, reducing the risk of local cracking or indentation later.
Confirming point-load areas perform as specified
Strength results taken at or near racking leg locations give direct evidence that the point-load detail has performed as intended.
A commissioning record naming the exact leg locations tested avoids ambiguity about which readings back up the point-load detail.
Protecting a floor under known point loads
Where racking or machinery is due to be installed, boarding should stay down until strength testing confirms the floor can take the loads named in the specification.
Around racking leg locations, agreeing a tolerance for making good stops minor surface marks being treated as structural defects.
Planning racking or heavy equipment on a new floor?
Let us know the loads involved before the screed is specified so depth and strength class can be checked.
Or call our landline on 01392 237700
Point loads and racking — your questions
In short
Concentrated point loads need specific attention in a screed specification, since a floor that copes with general foot traffic can still fail locally under a racking leg.
Planning racking or heavy equipment on a new floor?
Let us know the loads involved before the screed is specified so depth and strength class can be checked.