Traditional

Traditional Plasters

Sympathetic with older walls

Before World War II it was very difficult to reach the temperatures to economically fire the plaster of what is commonly seen today. All lath and pre war walls I have seen in the home have been formed using Lime. Natural Hydraulic Lime (not to be confused with Hydrated Lime) comes in three strengths for interior and exterior walls. Easy to mix, difficult to apply and slighty more expensive than Modern Plaster. NHL has several properties which are sympathetic to pre war houses.

Damp issues & “breathing”

It is not uncommon to see damp issues arise around interior walls that are originally composed of Natural Hydraulic Lime under the surface of Modern Plaster but have been repaird with modern plaster. Apart from Artex, Modern Plasters do not allow water or oxygen to flow through. Lime Plaster is water permeable and thus allows damp areas to chemically move out of the wall. It’s rather long and interesting science, and makes an interesting read. Take a look at buying this book (or lending from me) for further explanation. However, understanding how water flows, heats up and evapourates is important for homes that are in areas exposed to so much water in our damp climate as our own. Exterior natural stones and brick pointed with Portland Cement, often show signs of errosion because the water cannot flow through the pointing. It continues to linger in the stone and errodes faster. The same can be true for larger walls in bedrooms, around windows replaced with modern plasters. Generally the further away from wet or rain the safer it is to plaster with modern plasters over traditional plasters.

The solution

The solution is obviously to remove modern plaster that is causing the failure of moisture to move freely, and to do this would be to use NHL to plaster indoors or alternatively render outside. A 25kg bag of NHL 3 costs around £25 and washed plastering sand costs very little. The cost of a Lime Finish is more expensive and has to be transported from the mainland is pre slaked tubs. A 10kg tub including postage costs around £20. Although in the long term its cheaper to replace the lime mortar every hundred years than to replace the bricks every ten years.
© This site was packaged and coded by Xara, designed using Xara Web Designer by Alexander Wilson.
Exterior Lime preservation work at Osborne House.

Lath ceilings and cracks

Old lime and plaster ceilings attached to lath are notorious for deep cracks. This is fairly common if the original plaster is nearly a century old.. Its actually a testament to traditional plaster if the ceiling can last a century with only a few cracks, however its usually age and strength that causes the cracks. Several approaches can be taken to remedy this problem.These cracks can be channeled out and repaired with plaster of paris for a temporary solution. Although another, long term, approach would be to take down all the lath and plaster, check your timber joists are strong and reboard with a modern plasterboard, for either taping and jointing or a thistle finish plaster. Two other remedies can be done. To find the joists and to reboard over the exsisting lath and plaster ceiling. However you must bear in mind that you are adding more weight to your timber joists. Which is fine if they are strong, but if they have had water rot (As I have experienced) then its likely not a very good solution. The final remedy would be to take down all lath and plaster, and relath the ceiling and use traditional methods which is a dying skill in todays industry and would likely take more time and meaning investing more money.

Tiling over lime plaster

Ideally you want to avoid tiling over lime plaster walls if the walls are frail (perhaps you may want to replaster  the wall first before tiling over as its impossible to replaster a traditional wall with tiles on). If the wall is in good condition you should ask your tiler to use a Pure Lime Grout. Such as found here and even use a lime based tile adhesive. It should be noted also that if you remove coving and skirting then you’d be good to screw HardieBacker® Board to your joists and tile over the HardieBacker® Board without the need to replaster or remove old plaster.
Decorator & Plasterer

Traditional

Plasters

Sympathetic with

older walls

Before World War II it was very difficult to reach the temperatures to economically fire the plaster of what is commonly seen today. All lath and pre war walls I have seen in the home have been formed using Lime. Natural Hydraulic Lime (not to be confused with Hydrated Lime) comes in three strengths for interior and exterior walls. Easy to mix, difficult to apply and slighty more expensive than Modern Plaster. NHL has several properties which are sympathetic to pre war houses.

Damp issues &

“breathing”

It is not uncommon to see damp issues arise around interior walls that are originally composed of Natural Hydraulic Lime under the surface of Modern Plaster but have been repaird with modern plaster. Apart from Artex, Modern Plasters do not allow water or oxygen to flow through. Lime Plaster is water permeable and thus allows damp areas to chemically move out of the wall. It’s rather long and interesting science, and makes an interesting read. Take a look at buying this book (or lending from me) for further explanation. However, understanding how water flows, heats up and evapourates is important for homes that are in areas exposed to so much water in our damp climate as our own. Exterior natural stones and brick pointed with Portland Cement, often show signs of errosion because the water cannot flow through the pointing. It continues to linger in the stone and errodes faster. The same can be true for larger walls in bedrooms, around windows replaced with modern plasters. Generally the further away from wet or rain the safer it is to plaster with modern plasters over traditional plasters.

The solution

The solution is obviously to remove modern plaster that is causing the failure of moisture to move freely, and to do this would be to use NHL to plaster indoors or alternatively render outside. A 25kg bag of NHL 3 costs around £25 and washed plastering sand costs very little. The cost of a Lime Finish is more expensive and has to be transported from the mainland is pre slaked tubs. A 10kg tub including postage costs around £20. Although in the long term its cheaper to replace the lime mortar every hundred years than to replace the bricks every ten years.
© This site was packaged and coded by Xara, designed using Xara Web Designer by Alexander Wilson.