OK how do you lay a hearth stone?
Poll: OK how do you lay a hearth stone?
Total Members Polled: 40
Discussion
Belated update...
In the end I took advice from the stone mason, who has laid many hearths. He said there was no need to do it in sections, gave me some BAL tile adhesive, recommended dot and dab, and described the packing route as Binns suggested. He said the adhesive would suck the hearth down onto the packers.
This proved to be an excellent idea. To prevent rocking I used three sections of spare wood strip, and discovered that the existing concrete bed was actually a few mm low on one side. Hence some packing pieces were added until the triangle was exactly level in all directions.
Then to the hearth - a single slab about 75kg that two people could barely lift, and certainly not place carefully into an alcove without mishap. So I dug out a little set of little wheels that someone had given me for moving white goods and we set it all up 'ready to roll'.
I tied strings to the wheel bogies so we could get them out afterwards, and we did a dry run in and out to make sure the hearth would fit in the cavity. It did.
Then I splodged dabs of tile adhesive around the ground, taking care to leave two 'tracks' for the wheels to run in and out. Then after a deep breath we carefully rolled the hearth into place through the field of dabs. Lift up the front a little, pull the wheel bogies out by the strings, and lower the hearth onto the packing pieces. Newton did the rest.
It sounded rather hollow at first, and I thought I hadn't used enough adhesive, but as the adhesive and hearth dried out (it took a week!) it sounded nice and solid.
It now has a 75kg stove on it and about 100kg of marble surround, and is just fine. And contrary to popular belief, it doesn't get very hot underneath the stove so sections weren't necessary.
It shows that the mason was right in every respect and that careful planning is the way to fit a 75kg hearth that no-one can lift, to within a millimetre
In the end I took advice from the stone mason, who has laid many hearths. He said there was no need to do it in sections, gave me some BAL tile adhesive, recommended dot and dab, and described the packing route as Binns suggested. He said the adhesive would suck the hearth down onto the packers.
This proved to be an excellent idea. To prevent rocking I used three sections of spare wood strip, and discovered that the existing concrete bed was actually a few mm low on one side. Hence some packing pieces were added until the triangle was exactly level in all directions.
Then to the hearth - a single slab about 75kg that two people could barely lift, and certainly not place carefully into an alcove without mishap. So I dug out a little set of little wheels that someone had given me for moving white goods and we set it all up 'ready to roll'.
I tied strings to the wheel bogies so we could get them out afterwards, and we did a dry run in and out to make sure the hearth would fit in the cavity. It did.
Then I splodged dabs of tile adhesive around the ground, taking care to leave two 'tracks' for the wheels to run in and out. Then after a deep breath we carefully rolled the hearth into place through the field of dabs. Lift up the front a little, pull the wheel bogies out by the strings, and lower the hearth onto the packing pieces. Newton did the rest.
It sounded rather hollow at first, and I thought I hadn't used enough adhesive, but as the adhesive and hearth dried out (it took a week!) it sounded nice and solid.
It now has a 75kg stove on it and about 100kg of marble surround, and is just fine. And contrary to popular belief, it doesn't get very hot underneath the stove so sections weren't necessary.
It shows that the mason was right in every respect and that careful planning is the way to fit a 75kg hearth that no-one can lift, to within a millimetre
Lime mortar is usually recommended as it allows more expansion movement than cemented mortar.
I know you are asking about a stove but when you fit a cast iron arch open fire it is essential that there are no air voids behind the panel as this can cause expansion issues and cause cracking. It is isually recommended to backfill slowly with broken engineering brick and lime mortals all the way up to the throat of the opening and then higher to the sides and rear and make a smooth finish to slope from back to front which allows any moisture or debris to come back down the opening rather than build up at the back and cause issues.
If I doubt call your local fireplace specialist!
I know you are asking about a stove but when you fit a cast iron arch open fire it is essential that there are no air voids behind the panel as this can cause expansion issues and cause cracking. It is isually recommended to backfill slowly with broken engineering brick and lime mortals all the way up to the throat of the opening and then higher to the sides and rear and make a smooth finish to slope from back to front which allows any moisture or debris to come back down the opening rather than build up at the back and cause issues.
If I doubt call your local fireplace specialist!
ace 
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