Flint Walls Flint is an impervious material that is very hard, but it does not need to be set in a very strong mortar. Lime mortar is a type of mortar mix that was very popular with skilled artisans and masons during the late 1800s and 1900s. 2. So you can't … thanks Mike Render Mortar Mix (Modern Buildings) The curing time of lime is longer than that of cement and if the area/wall is exposed to weathering it needs to be protected sufficiently. It allows moisture to evaporate and walls to breathe. As an example, you may think that with flint being virtually impervious and extremely hard that cement or a hard lime mix would be okay. and the aftercare/curing requires more as lime pointing needs to be tamped/beaten back with a stiff brush as this action removes excess mortar and sets the mortar into the joint. Using lime mortar can decrease the need for and frequency of expansion joints. The correct mortar mix varies between structures, but the general rule of thumb is that the mortar should be weaker than the surrounding bricks/stone. Knapped flints are nodules split to achieve a deliberate aesthetic effect rather than those simply fractured, ie broken naturally or crudely severed to reduce them to a convenient size. Dry powder lime mortar: Heritage Mortar / NHL & Natural Mortar /NHL 25kg bag will repoint 3 to 4 m2 brickwork or lay approx. The lime mortar should always be softer than the stone and generally I use a 4:1 mix. Strong cement mortar is wrong to use, as the water that enters the wall through tiny cracks will not be able to dry out. Speaking as the owner of a very large flint wall (Listed GII), we had to rebuild a section which was demolished by a tree. Pointing Calculator. 25 bricks. This is known as galleting. 1000 bricks. The Myth in the Mix The 1:3 ratio of lime to sand Gerard Lynch. What is knapped flint? Home Work Services Flint Types Team Blog Contact. Mortar Calculator . An absence of grit or aggregate greater than 3-4mm in the joints of the brickwork is normally all that differs from the mortar of the brick & that of the flint. This is huge shame as, when done well, repointing brickwork is a job that can really enhance a home, despite its seeming insignificance. In fact, many people still consider lime mortar to be superior to many types of modern mortar mixes. Lime mortar is weaker than bricks, masonry and stones, yet it is able to support the full weight of a structure, allowing buildings to flex and move. FLINT WALL BLOG. They can be stacked without mortar, but this requires stacking them just so. This wall size coverage calculator will provide you with an estimate of how much premixed hydraulic lime mortar would be required for standard size brickwork (215mm x 102.5mm x 65mm, working to a 10mm joint). The amount of pozzolan added will vary according to the hardness of the masonry and the degree of exposure of a site. Answered 1st Aug 2011 Liked 21. bricky1. Here at Sussex Lime Plastering we can take a sample of your mortar and have it analysed to get as close to the original mortar as possible. Location: Chichester. There are four main types of mortar mix: N, O, S, and M. Each type is mixed with a different ratio of cement, lime, and sand to produce specific performance characteristics such as flexibility, bonding properties, and compressive strength. Estimate mortar quantity for building and bedding with bricks or blocks. The lime adds some flexibility. It clearly indicates how easy the Point Master makes this previously highly difficult job. This shows squared stone with a narrow flush joint. Walls can be approximately dated by their coursing, mortar composition and whether flints are used whole, fractured or knapped. and Repair of Flint Walls”, Technical Pamphlet 16, with kind permission of the Society for the Protection of Ancient Buildings. This is not normally used now. This is a section of brick and flint wall at the front of North Lodge of approximately 1600mm height. Our skilled craftsmen used a lime mortar mix with new flint and stone work to match in with the conservation area. It is a low strength mortar with minimum 2.5 MPa (350 psi). Adding mortar makes your wall stable and takes the worry away. Colour Chart. In recent building-site history, mixing mortar has become a job for the general labourer, despite often being unqualified and poorly skilled. On edge coping at the junction with the conservation area in kilograms from the number of bricks, area! Of pozzolan added for use on older Victorian style or brick homes were. 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