General External Stone Advice
Our external stone range currently comprises 13 of our limestones that are dense enough to be used externally as well as internally (or have 3cm thick dedicated formats). Whether you are searching for a traditional limestone to be used outside or you want to achieve that seemless flow inside to out where large bi-fold doors are specified, our external limestones offer beautiful finishes with great value for money.
Installation of external stone depends on the colour and density of the stone.
All these limestones can be laid onto an MOT type 1 hardcore base with a wet sand & mortar mix or onto a prepared concrete pad using the same mortar mix OR a frost proof grey tile adhesive. Whichever system is used a full bed or mortar/adhesive must be used - dot & dabbing will result in broken stone. SBR must be added into the mortar mix to give added flexibility.
All these limestones can be laid onto an MOT type 1 hardcore base with a wet sand & mortar mix BUT white portland cement must be used. You can also install onto a prepared concrete pad using the same mortar mix OR a frost proof white tile adhesive. Whichever system is used a full bed or mortar/adhesive must be used - dot & dabbing will result in broken stone. SBR must be added into the mortar mix to give added flexibility. Avignon, Castile, Hebron Cream, Dijon & Regent all have dedicated 3cm thick external formats, thicknesses less than this should not be used externally.
If laying onto an MOT base then sealing is purely an aesthetic decision, the stone does not need to be sealed. If laying onto a prepared concrete pad we recommend to seal the stone to minimise water ingress.
