Hi all, long time lurker, first time poster!
After a bit of advice on concreting the floor of a new garage that I've built over the top of a previously existing garage...
It's a steel framed and clad monster, with posts either sitting on newly created 300x300x600 concrete pads or sat on top of existing concrete that is about 150mm deep and been around for 60 years. I'm planning to lay inside the walls, not create a pad to sit the frame on if that makes sense.
The floor as it is was laid in 4 or 5 different sections it seems over the years - varying from 50mm deep to some parts which after investigation are around 100mm deep laid on top of another layer of 50mm concrete on top of another 50mm of hardcore, comprising of bricks, more broken up concrete, broken pottery and anything else they could find just after WWII!
Getting to the point - to make an even level over the top of all of this means laying new over the top - I'm thinking of making one side 50mm (figure thats the minimum I can get away with?) above existing, which would make the other side 180mm deep!
Now the questions:
1. Should I be worrying about putting some sub-base in the deep end, or just fill it all with concrete? Could I fill in some of the really deep parts with big lumps of an old pathway laid upside down on the old stuff, would still leave at least 100mm space on top for new concrete. Hmmm I may have found somewhere to get rid of the remaining asbestos sheets off the old roof!
2. Aiming to paint the concrete after its cured, with this depth of old concrete underneath and new on top, is a DPC needed?
3. Will new concrete stick to old? One area has had a 6mm screed over a thin bed of sand at some point which has cracked over time and has now been removed leaving a sandy finish to the concrete underneath, should I throw some watered down PVA over that to seal?
4. Am I worrying too much and should just get mixing and throw the stuff in there?
After a bit of advice on concreting the floor of a new garage that I've built over the top of a previously existing garage...
It's a steel framed and clad monster, with posts either sitting on newly created 300x300x600 concrete pads or sat on top of existing concrete that is about 150mm deep and been around for 60 years. I'm planning to lay inside the walls, not create a pad to sit the frame on if that makes sense.
The floor as it is was laid in 4 or 5 different sections it seems over the years - varying from 50mm deep to some parts which after investigation are around 100mm deep laid on top of another layer of 50mm concrete on top of another 50mm of hardcore, comprising of bricks, more broken up concrete, broken pottery and anything else they could find just after WWII!
Getting to the point - to make an even level over the top of all of this means laying new over the top - I'm thinking of making one side 50mm (figure thats the minimum I can get away with?) above existing, which would make the other side 180mm deep!
Now the questions:
1. Should I be worrying about putting some sub-base in the deep end, or just fill it all with concrete? Could I fill in some of the really deep parts with big lumps of an old pathway laid upside down on the old stuff, would still leave at least 100mm space on top for new concrete. Hmmm I may have found somewhere to get rid of the remaining asbestos sheets off the old roof!
2. Aiming to paint the concrete after its cured, with this depth of old concrete underneath and new on top, is a DPC needed?
3. Will new concrete stick to old? One area has had a 6mm screed over a thin bed of sand at some point which has cracked over time and has now been removed leaving a sandy finish to the concrete underneath, should I throw some watered down PVA over that to seal?
4. Am I worrying too much and should just get mixing and throw the stuff in there?
