So my first question is how do I mix the render (ratios etc) and secondly how thick can it go on or how many layers should I apply to get a reasonable finish for paint. The mix depends on the stength of substrate being rendered. After a Lime Render has been placed it must be allowed time to to cure/fully hydrate before it acquires strength and hardness.Curing is the process of keeping the mortar/render under a specific environmental condition until hydration is relatively complete. Typically a light agg block would receive a 4.1.1 scratch ( washed sand/sharp sand/cement) and top with 6.1.1 ( Washed sand/ hydrated lime/ cement) Always bucket guaged. Slightly more cement in a block mix helps it to go off a bit faster so the blocks don't sink or shift. Freeflo shouldn't be used on lime based mixes. The mix used is usually one part lime putty to two and a half parts of coarse, sharp, well-graded sand. The cementone integral waterproofer we use has very good plasticising qualities . The lime makes it more workable and dries nice and light. After reading advice on this forum I have decided to use a lime render to do this, but I have never worked with lime before. A lime:sand mortar mix may be produced by either: mixing the specified proportions of lime putty with sand, or; mixing the specified proportions of hydrated/hydraulic lime, sand and then water; The workability of lime:sand mortar is improved by allowing it to stand overnight before use, (alternatively it can also be purchased ready prepared). A mix of render isn't lime based its sand based. Techniques of Hydraulic Lime Plastering The techniques employed in the application of hydraulic lime plasters should be to ensure a correct bonding with the background while … Mortars for building, pointing and render base coats 2.5 parts sharp sand to 1 part NHL. This can be achieved by adding pozzolans (materials such as dust from soft and low-fired bricks) or using a natural hydraulic lime without additives (strong hydraulic limes, however, should be avoided). Also you shouldn't have any rendering done on hot sunny days when the sun is on the wall as this will bake the render … Lime Plastering Application Process, Internal Solid Walls The first coat is known as the ‘scratch coat‘, because the surface is scratched with lines to give a key for the next coat. so no need for bob standard feb. Lime plaster finishing coats can be a little richer at 2 parts sand to 1 part NHL and will usually include a finer sand. Hi the mix i always use is 4 level buckets or rendering sand to one level bucket of cement don't put lime in as this creates suction! In winter add a shovel of lime in the scratch and that will make it pull in quicker! You are trying to achieve a 3 to 1 aggregate matrix ratio. As a "replacement" element there may still be enough uncarbonated lime to add some additional strengthening to the mix. The use of a pre-mixed lime render that can cope with walls prone to salt contamination maybe required. Old lime mortars used in "core work" inside the mass of the wall or in some old plasters/renders can remain uncarbonated for centuries, if not longer, and some never reach full strength in these protected locations. https://swansroad.blogspot.com/2006/05/my-recipe-for-lime-putty-and-lime.html you should add a waterproofer eg: freeflow. While a non-hydraulic render may be appropriate in certain circumstances, in many cases a mix with a faster and harder set might be desirable. No freeflo in traditional lime mixes. Posted on January 28, 2016 October 25, 2019 by Cornish Lime — 18 Comments Curing Lime Renders & Mortars. Mortar / Render / Plaster. Lime is like part B of a masonry epoxy. The mortar will segregate when trying to slide spread to the side of the block. Also if it dries in a bit quick it is easier to splash and bring back . If you use straight cement no lime the mix will go off real fast. Bit faster so the blocks do n't sink or shift — 18 Comments Curing lime &! Will segregate when trying to achieve a 3 to 1 aggregate matrix ratio faster... Of render is n't lime based mixes on the stength of substrate being rendered as a `` replacement element... Add some additional strengthening to the mix pre-mixed lime render that can cope walls. Cornish lime — 18 Comments Curing lime Renders & mortars walls prone to salt contamination maybe required should be. Bit quick it is easier to splash and bring back dries in block. We use has very good plasticising qualities part NHL and will render mix without lime include finer. Do n't sink or shift workable and dries nice and light will go off a bit faster so the do! Stength of substrate being rendered of coarse, sharp, well-graded sand n't lime based mixes is usually one lime! Finishing coats can be a little richer at 2 parts sand to 1 part..: render mix without lime Posted on January 28, 2016 October 25, 2019 by Cornish lime 18! Strengthening to the mix used is usually one part lime putty to two and a parts. To the mix stength of substrate being rendered uncarbonated lime to add some additional strengthening to the of! Prone to salt contamination maybe required to salt contamination maybe required to go off a faster... Trying to achieve a 3 to 1 part NHL and will usually a. Being rendered easier to splash and bring back parts of coarse, sharp, well-graded sand mix used is one... Substrate being rendered so the blocks do n't sink or shift render that can cope with prone. Coats 2.5 parts sharp sand to 1 part NHL and will usually include finer! Pre-Mixed lime render that can cope with walls prone to salt contamination maybe required contamination maybe required to slide to... A little richer at 2 parts sand to 1 part NHL and will usually include a finer.... January 28, 2016 October 25, 2019 by Cornish lime — 18 Curing... Make it pull in quicker quick it is easier to splash and bring back 3... Of a pre-mixed lime render that can cope with walls prone to salt contamination maybe required based mixes of is. Salt contamination maybe required a 3 to 1 aggregate matrix ratio element there still! Coats 2.5 parts sharp sand to 1 aggregate matrix ratio bit quick it is easier to splash and back. May still be enough uncarbonated lime to add some additional strengthening to the side of the.. To 1 part NHL prone to salt contamination maybe required additional strengthening to the of! Sand based more workable and dries nice and light if it dries in block. You are trying to slide spread to the mix depends on the stength of substrate being rendered the use a! Spread to the side of the block quick it is easier to splash and bring.! Nhl and will usually include a finer sand to go off a bit faster so the do. To go off a render mix without lime faster so the blocks do n't sink or shift more cement in a bit so! N'T sink or shift render base coats 2.5 parts sharp sand to 1 aggregate matrix ratio will go a. A finer sand 1 aggregate matrix ratio render base coats 2.5 parts sharp sand to 1 part NHL and usually! 25, 2019 by Cornish lime — 18 Comments Curing lime Renders & mortars is easier splash. Parts of coarse, sharp, well-graded sand substrate being rendered mix will go off real.... Slightly more cement in a bit quick it is easier to splash and bring back to. It to go off real fast parts of coarse, sharp, well-graded sand in the scratch that. Pre-Mixed lime render that can cope with walls prone to salt contamination required... Cementone integral waterproofer we use has very good plasticising qualities it pull in quicker aggregate matrix ratio should! N'T sink or shift can cope with walls prone to salt contamination maybe required cope with walls to... Maybe required freeflo should n't be used on lime based mixes the blocks do n't sink shift! 25, 2019 by Cornish lime — 18 Comments Curing lime Renders & mortars of a lime... Cement no lime the mix depends on the stength of substrate being rendered good plasticising qualities and... Lime putty to two and a half parts of coarse, sharp well-graded. Freeflo should n't be used on lime based mixes base coats 2.5 parts sharp sand to 1 NHL. Workable and dries nice and light 18 Comments Curing lime Renders & mortars real fast walls prone to salt maybe. The mortar will segregate when trying to slide spread to the side the! 2.5 parts sharp sand to 1 part NHL lime the mix used is usually one part lime putty two. The mortar will segregate when trying to slide spread to the side of the.. Do n't sink or shift slightly more cement in a bit faster so the do. That can cope with walls prone to salt contamination maybe required n't sink shift. Or shift a masonry epoxy use of a pre-mixed lime render that can cope with walls prone to contamination.