The Stoneleaf SL11 Natural Roof Slate

Stoneleaf SL11 natural roof slate is extremely flat with a smooth even texture. The SL11 is a fine choice for both period properties and modern homes guaranteed to enhance the individual character of any building.
Natural slate is a great choice for homeowners who are looking for a beautiful, durable, and low-maintenance roofing material.

The SL11 are graded and suppiled into 2 thicknesses, 5mm and 6mm. This additional sorting process means they require very little on site sorting, making them more economical to lay as less need to be rejected or wasted. 

Popular Roof Slates in Inches & Metric Sizes

The SL11 is available in a wide range of traditional imperial sizes, making it the perfect match for UK heritage projects. While we stock standard metric units, we specialize in the most in-demand roof slates in inches, including:

  • 20x10 (500mm x 250mm) – Our most popular versatile size.

  • 20x12 (500mm x 300mm) – Ideal for lower pitches.

  • 24x12 (600mm x 300mm) – A classic large-format slate.

  • 24x14 (600mm x 350mm) – Perfect for expansive roof slopes.

  • 22x11 (550mm x 275mm) – A traditional regional favorite.

Other imperial and metric sizes are available upon request to suit your specific project requirements.

Stoneleaf SL11 natural roof slates shown in various imperial sizes, including 20x10, 20x12, 22x11, 24x12, and 24x14 inches

Case Study - Writtle Renovation

The Stoneleaf SL11 fitted the bill for this renovation project in Writtle. The developer was looking for a slate that wouldn't break the bank but still lays flat, is easy to sort and isn't fragile like glass (like many cheaper slates can be). The varying shades of colour in the SL11 adds to the character of this property with its decorative brickwork and chimneys.

Specification:

Source:
China

Approx. Thickness:
5mm or 6mm

Colour:
Blue Grey

Texture:
Smooth

Sizes Available:
Metric: 500 x 250mm, 500 x 300mm,
Imperial: 20x12" (510x305mm), 22x11" (560x280mm), 24x12" (610 x 305mm), 24x14" (610 x 355mm)

Grades:
Best Only

Pre-Holing 500 x 250mm:
90mm lap

Coverage 500 x 250mm:
19.1 per M2

Slate and a Half:
Available un-holed

Strength:
Good flexural strength both transversely and longitudinally. Due to the vast distance the slates are transported, a recommended 5% breakage allowance should be applied.

Approx. Weight:
36kg/ M2 based on 500 x 250mm 6mm

Guarantee:
75 year site specific guarantee available upon request

Myona Roofing found the Stoneleaf S11 to be a good quality slate with a consistent finish. This meant that not only were Deanfield Homes happy with the overall effectiveness and aesthetics, complementing the professional standard they demand, we were also able to judge the required quantities with minimal wastage. The support received from Stoneleaf meant ordering and delivery was seamless and we would happily use this product again.

Test Category

Water Absorption
Thermal Cycling
Sulphur Dioxide
Dimensionality
Strength

Rating/Result

W1 (A1)
T1
S1
0.0%
69 MPa

The Benefit to You

Maximum Frost Resistance. Low 0.29% absorption means no risk of freeze-thaw damage.
No Rusting. Zero oxidation of metallic minerals ensures no unsightly brown streaks.
No Delamination. Highest resistance to acid rain—will not split or soften over time.
Flatness Faster Install. Perfectly flat slates require less sorting and less skilled labor to lay.
High Load Bearing. Built to withstand extreme wind speeds and heavy snow loads.

Slate fixing Guide

Follow Good Practice for Slating to achieve best result on every project.

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Headlap Tables

Minimum Recommended Headlap B.S.5534 for nail fixing.

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Guide to Hook Fixing

A simple guide to hook fixing including headlap tables.

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