SKU: eb9c081b0f03 Categories: Aggregates, Cement & Plaster, BAGGED, Building Materials Tags: lime mortar, nhl lime

NHL 3.5 LIME MORTAR (medium)

£24.00 + Vat

2 in stock (can be backordered)

National Pallet Delivery
In store click & collect
Quality reclaimed products

Product Info

NHL 3.5 LIME MORTAR (medium)

All the materials you need are packed inside the bag:

Natural Hydraulic Lime (NHL)
Blended Sands & Aggregates

The lime, sands and aggregate are carefully selected and sourced from around the British Isles.

The manufacturer for this product is Conserv

Hydraulic Lime Mortar is a breathable restoration mortar that is typically used for historic masonry that must tolerate extreme weather and/or persistently damp conditions. Like Portland cement-based mortars the primary chemical curing reaction is rapid and hydraulic. This means it sets quickly, even in damp environments. Unlike Portland cement-based mortars, which can be extremely rigid and brittle, natural hydraulic lime mortar has a low modulus of elasticity. This makes the mortar flexible, absorbing natural movement in masonry walls to resist damage to masonry units during adverse conditions.

Find more roofing supplies here.

Weight	25 kg

Slate Calculator

Slating Headlap

Lap

Expandable Headlap Info

Choosing Headlap

Definition: The vertical overlap between successive rows of tiles to prevent water ingress.

Factors to consider:

Roof pitch: Shallower pitches (< 30°) need 75–100 mm; steeper (> 45°) can use 50 mm.
Climate & exposure: Wind-driven rain or heavy rainfall zones benefit from more headlap.
Tile profile: Deeper tiles may require extra overlap to seal correctly.

Rule of thumb:

Standard (30–45°): 50–75 mm
Low (< 30°): 75–100 mm
High (> 45°): 50 mm

Slate Size / Type

Slate 50mm Lap

Selecting Tile Size

Coverage per tile: Larger tiles cover more area but are heavier, affecting handling and substrate load.

Aesthetic scale: Big tiles suit modern, minimal lines on large roofs; smaller tiles give more texture and a traditional look.

Structural limits: Check rafters and battens can support the chosen tile’s weight and fixing centres.

Installation speed vs. waste: Larger tiles lay faster but may require more cutting at edges, increasing waste. Smaller tiles take longer but can reduce off-cuts.

Compatibility: Ensure the tile size works with your chosen headlap & side-lap for correct coverage per m².

By balancing pitch, weather, substrate capacity and appearance, you’ll pick the optimal tile size for performance and style.

Slate 75mm Lap

Selecting Tile Size

Coverage per tile: Larger tiles cover more area but are heavier, affecting handling and substrate load.

Aesthetic scale: Big tiles suit modern, minimal lines on large roofs; smaller tiles give more texture and a traditional look.

Structural limits: Check rafters and battens can support the chosen tile’s weight and fixing centres.

Installation speed vs. waste: Larger tiles lay faster but may require more cutting at edges, increasing waste. Smaller tiles take longer but can reduce off-cuts.

Compatibility: Ensure the tile size works with your chosen headlap & side-lap for correct coverage per m².

By balancing pitch, weather, substrate capacity and appearance, you’ll pick the optimal tile size for performance and style.

Slate 100mm Lap

Selecting Tile Size

Coverage per tile: Larger tiles cover more area but are heavier, affecting handling and substrate load.

Aesthetic scale: Big tiles suit modern, minimal lines on large roofs; smaller tiles give more texture and a traditional look.

Structural limits: Check rafters and battens can support the chosen tile’s weight and fixing centres.

Installation speed vs. waste: Larger tiles lay faster but may require more cutting at edges, increasing waste. Smaller tiles take longer but can reduce off-cuts.

Compatibility: Ensure the tile size works with your chosen headlap & side-lap for correct coverage per m².

By balancing pitch, weather, substrate capacity and appearance, you’ll pick the optimal tile size for performance and style.

Slates Per m2

Expandable Slates per m² Info

Calculating Slates per m²

Definition: Number of slates needed to cover one square metre.

Formula: 1 000 000 mm² ÷ (effective width × effective height)

Where:

Effective width = tile width – side lap
Effective height = tile height – head lap

Example: 610 mm × 355 mm tile, 20 mm side lap, 75 mm head lap:

Effective width: 610 − 20 = 590 mm
Effective height: 355 − 75 = 280 mm
Area per slate: 590 × 280 = 165 200 mm²
Slates per m²: 1 000 000 ÷ 165 200 ≈ 6.05

Adjust your headlap and sidelap values for precise coverage calculations.

Slate Required(Required)

Measure Your Roof Area

Determining Your Roof’s Area (m²) Accurately measuring your roof is essential to estimate how much slate you’ll need. Follow these steps: Measure the rafter length Runs from the gutter up to the ridge line.

Width (m)

Length (m)

Total Mtr²

Total Slates Required

Copper Nails Total KG

Expandable Copper Nails Info

Copper Nails for Slating: Overview & Specs

Why use copper nails?

Corrosion resistance: Forms a protective patina to prevent rust and staining.
Superior durability: Lasts for decades without needing replacement.
Optimal flexibility: Absorbs roof movement without cracking or shearing.
Aesthetic harmony: Weathers to a warm patina that complements natural slate.
Chemical compatibility: No galvanic reaction with slate or lead flashings.

Packaging & usage: