Thermal bridging (cold bridging/heat bridging) occurs when the insulation layer is penetrated by a material with a high thermal conductivity. If not insulated it can create condensation, damp, and could lead to mould.
Part L section 1a 'reasonable provision shall be made for the conservation of fuel and power in buildings by limiting heat gains and losses through thermal element and other parts or the buildings fabric'.
Galvanic corrosion is the preferential corrosion that occurs when dissimilar metals are in contact in the presence of an electrolyte.
Ways to reduce risk:
Avoid contact between dissimilar metals
Avoid a difference of more than 0.015 anodic index value.
What to consider:
Firstly, consideration must be made of the number of anchors which are being used. Quite simply, the more points the façade is penetrated the more potential areas of thermal bridging.
Choosing an anchor which has very good thermal performance, but poor structural performance is likely to not only cost more but not provide the thermal benefit of having a similar performing thermal anchor which enable fewer connections to be used.
The Glide on balcony system is considerably lighter in weight (primarily because of its aluminium construction) and the anchors used are considerably stronger than other options available which both mean that the number of anchor connections required can be reduced, saving cost and minimising cold bridging.
Another consideration is the post-Grenfell ban on which prohibits the use of any combustible material on the exterior of buildings over 18 metres. We have developed a solution here called the Stub Guard, and CNC cut shroud which fits snugly around your stubs provided great thermal performance of raising just 56 degrees over the ambient temperature after two hours (as opposed to the 180 degrees allowed).
The key ways we are able to dramatically reduce the overall number of façade penetrations are:
Our balconies are much lighter due to them being made of aluminium
Our Anchors use a m30 stud as opposed to the market average or 18-22mm.
We use a 2 part thermal break, the bottom part being a non compressible resin.