4.8 x 45mm Masonry Screws & 50mm Washers

Description

The Tekwarm UFH Masonry Screw and Washer Kit gives a secure fixing for Tekwarm 20mm UFH boards into concrete, screed and masonry substrates. Each box holds 100 self-tapping 4.8 x 45mm screws and 100 matching 50mm washers (stress plates), 200 components in total.

The countersunk, EvoShield coated screw is a self-tapping carbon steel fixing with a nail (pyramidal) point, used with a 4.35mm pilot hole. The 50mm stress plate spreads the load and stops the board pulling over the screw head, protecting the 20mm board.

4.8 x 45mm

Self-tapping screw

50mm

Washer / stress plate

100 + 100

Screws and washers

20mm

Board thickness

4.35mm

Pilot hole

5 minimum

Fixings per 1200 x 600mm board

Pre-drill a 4.35mm pilot hole for every fixing

A 4.35mm pilot hole is required in all substrate types, not just hard masonry. Keep surfaces clean and free from dust, hold fixings at least 50mm apart and 50mm from edges in concrete, and keep installation torque below 3 Nm to avoid over-tightening.

For Tekwarm 20mm boards only

The screw suits fixtures from 0 to 20mm thick with a nominal 25mm embedment. Use at least 5 screws and washers per 1200 x 600mm board. For fixing into timber, use the Tekwarm timber screw and washer kit instead.

Why the stress plate matters

Stress plates should be used whenever fixing Tekwarm 20mm UFH boards to distribute the load and prevent the board being pulled over the head of the fastener.

Key features

Self-tapping masonry screw

4.8 x 45mm countersunk screw with a nail (pyramidal) point for concrete, screed and masonry.

EvoShield corrosion protection

Coated with EvoShield 500 hour NSST-resistant aluminium and zinc flake bound in resin.

50mm stress plates

100 steel washers distribute load evenly and prevent damage to the 20mm board.

Strong carbon steel

SAE C1022 carbon steel screw for a dependable fixing.

Complete kit

100 screws plus 100 washers in one box, so every fixing has its stress plate.

Designed for Tekwarm 20mm boards

Matched to Tekwarm 20mm UFH boards, with 25mm nominal embedment into the substrate.

Technical specification

Pack contents

Brand

Tekwarm

Manufacturer part number

PR008935

Screws

100 x 4.8 x 45mm self-tapping

Washers

100 x 50mm stress plates

Total components

200

Self-tapping screw

Size

4.8 x 45.0mm

Head

Countersunk

Drive

Phillips No. 2

Point

Nail (pyramidal)

Material

SAE C1022 carbon steel

Coating

EvoShield 500 hour NSST-resistant (aluminium/zinc flake bound in resin)

Fixture thickness

0 to 20mm

Stress plate / washer

Size

50mm diameter, round

Nominal thickness

0.5mm

Material

Carbon steel with Galvalume (aluminium and zinc) coating

Function

Distributes screw load and stops the board pulling over the screw head

Installation

Pilot hole

4.35mm, required for all substrate types

Clearance hole in board

6mm

Nominal embedment

25mm

Installation torque

Below 3 Nm

Minimum spacing

50mm

Concrete

Minimum member thickness 100mm; minimum edge distance 50mm

Fixings per board

At least 5 per 1200 x 600mm board

Substrates

Concrete, screed and masonry

Frequently asked questions

What is in the box?

The box holds 100 self-tapping 4.8 x 45mm screws and 100 matching 50mm washers (stress plates), 200 components in total.

Do I need to drill a pilot hole?

Yes. Drill a 4.35mm pilot hole into the substrate before fixing. This is required for all substrate types, not only harder masonry. Keep the surface clean and dust free.

How many fixings per board?

Use at least 5 screws and washers per 1200 x 600mm board, keeping a minimum 50mm spacing between fixings. A box of 100 therefore fixes at least 20 boards (about 14.4 m²).

Which boards and substrates is it for?

It is for Tekwarm 20mm UFH boards (fixtures up to 20mm thick) fixed into concrete, screed and masonry.

Why do I need the stress plate?

The plate distributes the load and prevents the board pulling over the screw head, so the 20mm board is not damaged.

How tight should I fix it?

Keep installation torque below 3 Nm. Over-tightening can damage the board or strip the pilot hole.

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Room Dimensions

Length (in m):

Width (in m):

Height (in m):

Room Type

Living Room

Bedroom

Kitchen

Bathroom

Conservatory

Hallway

Glazing Type

Single Glazed

Double Glazed

Triple Glazed

External Walls

0 Wall

1 Wall

2 Walls

3 Walls

4 Walls

Insulation Level

Poor

Average

Good (New Build)

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