Suitable for medium density masonry* Masonry Density Chart
NHL 3.5 Lime Mortar is suitable for most types of masonry used in general building work.*
- Facing bricks
- London Stock
- Reclaimed Bricks
- Handmade Bricks
Suitable for low to moderate exposure** Masonry Exposure Guide
NHL 3.5 Lime Mortar is used for external building work in most parts of the United Kingdom where exposure to wind driven rain is low to moderate.**
- Solid Walls
- Cavity Walls
- Garden Walls
Suitable for joints with a thickness of 10mm or more
Oakwood Tarn mortar has a medium texture and is suitable for bedding, pointing and repointing joints with a thickness of 10mm or more. Sometimes masonry has non-standard joints of varying thickness, this is very common with random stone walling. Where this is the case, find the narrowest joint in the structure and select a lime mortar suitable for that.
Hydraulic Lime Mortar is CE certified and is manufactured to British Standards BS EN 998-2:2016 following heritage guidelines.
Authentic, Pure and Simple
100% natural, breathable and sustainable. The mortar doesn't contain anything artificial, no additives or plasticisers and absolutely, certainly no cement.
It's All Inside the Bag
All the materials you need are packed inside:
- Natural Hydraulic Lime (NHL)
- Blended Sands & Aggregates
The lime, sands and aggregate are carefully selected and sourced from around the British Isles.
Easy to Mix
Mixing the mortar is really simple. All you need to do is stir the lime and aggregate together, then add clean water and mix to the correct consistency.
The product is mixed in its entirety using all the aggregate and natural hydraulic lime provided, this ensures consistent appearance and performance.
There is generally sufficient time to work with the mortar before it reaches an initial set. A little water can be added to the mortar as required throughout the day to keep it workable.
Integrity is Everything
As a heritage product, the hydraulic lime mortar's performance depends on the integrity of the natural material.
The tough, waterproof packaging keeps the material in perfect condition which is critical given it's hydraulic nature.
The material is not compromised in damp or wet conditions. It is also protected from internal condensation in hotter temperatures.
Economy & Convenience
These bags are popular with building contractors as they're economical and practical for projects large and small.
Orders for 8 or more bags are typically delivered using the UK's largest pallet network companies to keep delivery costs to a minimum.
If space is tight on-site you can call us to arrange partial delivery of your goods on different dates. We'll find a solution that works best for you.
Buy with Confidence
Lime mortars from Conserv come complete with clear, concise instructions and free technical support. Don't hesitate to call if you need any help.
- BS EN 998-2:2016
- 25kg (approx.)
- Medium Coarse
- NHL 3.5
BS EN 459-1:2015
- BS EN 13139-1:2015
- Bed size
- 10mm ≥
- 1,650 kg/m³ ± (at 91 days)
- Vapour permeability
- 0.74 grams / 100mm² / 24hrs ±
- Compressive strength
- 3.44 N/mm² ± (at 91 days)
- Flexural strength
- 1.31 N/mm² ± (at 91 days)
- Resistance to freeze thaw
- Resistance to sulphate exposure
- Very high
- Resistance to freeze thaw in sulphate conditions
- Capillary rise
(76-100mm in 6 hours)
- Mortar durability class
- 3 to 4
- Carbonation rate
- Initial set
- Overnight ±
- 90 days ±
- Shelf life
- Use within 12 months of purchase§
* Masonry density can vary by quarry, manufacturer, age and condition of material, this information serves only as a general guide, disclaimer.
** Exposure is approximated and can vary, this information is presented as a general guide, disclaimer.
† Technical data is approximated as it can vary significantly depending on various factors, particularly weather conditions. The information presented outlines typical behaviour you might expect in the United Kingdom with ambient temperatures of 10°C in sheltered areas with low exposure to wind and moisture. The information is nevertheless useful to establish the relative properties and performance of different products, disclaimer.
‡ The colour of the mortar will continue to lighten until it fully cures. This difference in colour can be quite dramatic. In good weather, the mortar will appear much lighter after 10 days.
§ Products should be stored with packaging unopened, natural hydraulic lime is vulnerable once open and exposed.
Disclaimer It is the customer's responsibility to determine the suitability of this product. Samples should be prepared and approved before complete application of this product. Appropriate testing should be undertaken prior to application where compressive strength or density are a critical factor.