Why should we use lime mortar`s in today`s modern construction world? This is a complicated question and i will try to give you as much detail as possible. First of all we should ask What is Lime Mortar?..
Lime Mortars were a traditional material used for laying bricks before the widespread introduction of Portland Cement. It is important to differentiate been Lime Based Mortars and Portland Cement in your brickwork if you intend repairs or additions to your building. Nothing could be worse for your old lime based mortar that binds your brickwork together if you use modern mortar mixes, old brickwork was designed to have movement to some extent. The reason most old brick built buildings are of a solid wall construction and very thick is because Lime Mortars can take a long time to harden, so the wall was made thicker to enable the builder`s to build more than 3ft high every month.
There are basically 2 types of lime used for traditional lime mortars – these can be separated by their reaction to either water or air.
This type of lime is totally reliant on air to re-bond and bond the bricks together, this process is very slow.
Hydraulic lime is a much easier mortar to use as it is mixed using water; drying times are much quicker and is preferred in many situations.
I have been deliberately brief on this subject to make you realise that this is a very specialised area of construction, professionals involved in the renovation of old building take many years to acquire this knowledge and you should always seek a highly skilled mason if you intend to do any extensive renovations on your property. If you have walls that have subsided, then don’t attempt to just to underpin that area, you will cause great stress loading points that could have disastrous results.
Old houses have to be treated with respect and apprecitation of the methods that were used to build them. I know these repairs can be expensive, but if you do them wrong, the results will be far worse. In my experience of old house`s it often amazes me how simple their construction is, there was no use of
• Damp Courses
• Wall Ties
….yet they are still standing after 100`s of years, i see far more cracking of bricks and render coats in a modern house than i do for an old house, the question has to be asked… should we be building such rigid strong buildings that have little or no flexibility? Now i am of course mainly talking about house building and i am certainly not a structural engineer, but time and time again we tend to ignore the past totally and think we know all the answers (i can think of another industry beginning with the letter “B” that could learn some lessons from the past)
If you own an old property get in the professionals, in my research for this article i realised how specialised it is, hence the reason i decided to not go into detail and pretend i am an expert. I do not usually put links to other articles in my posts, but i feel this is important to make you realise that you have to do the research, especially if you intend to do the work yourself, i ahve been in the building industry for 30 years and i would not attempt this type of renovation work without doing the research and consulting with the professionals.
The following websites seem to be a great resource and a good place to start your research. I have no affiliation with these sites.
If anyone knows of other great resources then let me know and i will add them to the list.