Allotment Gardening Advice Help Chat

Chatting => Design and Construction => Topic started by: mrs bouquet on May 30, 2020, 14:58

Title: Laying Concrete
Post by: mrs bouquet on May 30, 2020, 14:58
Can you lay new concrete onto existing.  A workman has told me no, but I don't think he wanted to do it.
Thanks,  Mrs Bouquet
Title: Re: Laying Concrete
Post by: mumofstig on May 30, 2020, 16:50
Depends  ;) A thin layer tends not to work but no reason a thick layer wouldn't Ö.
Title: Re: Laying Concrete
Post by: Growster... on May 30, 2020, 17:40
Of course you can, but as Mum says, the thickness needs to be more than a thin layer, say about four inches, otherwise it just cracks up.

Your man was probably a bit wary, as a proper job is to break up what's there, to make a decent hardcore bed for the blinding (a layer of sand on the broken hardcore), and the new stuff then goes on top.

What sort of job are you planning, as you may be able to use paving stones on a sand bed!

Title: Re: Laying Concrete
Post by: rowlandwells on May 30, 2020, 18:16
I've always broken up existing concreate before re-laying new concrete because although there's  a bit more work involved the new concrete seems to bind better to the hard core base and with the price of ready mix concreate you only want to do it once
Title: Re: Laying Concrete
Post by: mrs bouquet on May 31, 2020, 12:12
I need a new greenhouse, but the floor at present is about 3 to 4 inches lower than the patio outside the doorway.   If I accidentally leave the water tap on (which is inside) the floor will flood and I then have to sweep the water out.   As I must have a new greenhouse - no ifs, no buts - I must have the floor raised first, because the enclosure is the back of my garage, and then walled around to about 3ft.  I want to keep the walls and will be happy to put a purpose made greenhouse inside existing walls, but cannot get the exact size.
Therefore when it rains, it will fill up and flood !  Any more thoughts please.   Mrs B
Title: Re: Laying Concrete
Post by: Aunty on May 31, 2020, 17:27
Lay paving slabs on sand on top of the concrete would be my idea.
Title: Re: Laying Concrete
Post by: Growster... on May 31, 2020, 17:32
I need a new greenhouse, but the floor at present is about 3 to 4 inches lower than the patio outside the doorway.   If I accidentally leave the water tap on (which is inside) the floor will flood and I then have to sweep the water out.   As I must have a new greenhouse - no ifs, no buts - I must have the floor raised first, because the enclosure is the back of my garage, and then walled around to about 3ft.  I want to keep the walls and will be happy to put a purpose made greenhouse inside existing walls, but cannot get the exact size.
Therefore when it rains, it will fill up and flood !  Any more thoughts please.   Mrs B

So you have, in effect, a sunken area where your old GH went, and you want to raise it level with the patio?

As you're not doing anything structural on the new raised floor, apart from building a new GH, which isn't that heavy, I don't see why a layer of concrete in the 'hole' shouldn't do the trick! A builder could even make it an inch or so higher, (making a small step in of course), by building some formwork, and pouring concrete straight into the 'hole'.

Bit tricky without a pic, can you try and get one for us?
Title: Re: Laying Concrete
Post by: mrs bouquet on June 03, 2020, 13:15
the old greenhouse, is built on brick walls, so the only part that would need to be shuttered would be where the doorway is.   He would need to take the sliding door off, as it would be in the way.  I think it measures about 10 x 8 ft, which at say 4 inches would be a metre of concrete.    My idea is that when the floor is done, all the old can be removed and then consider what to replace it with.   2 side of the walls, are my garage !!
If I try to break the existing up, how would I do that, would I need to use a pneumatic drill.  Thanks folk, Mrs B
Title: Re: Laying Concrete
Post by: jezza on June 04, 2020, 13:08
Hello I've just hoped a mate lay a concrete floor in a conservatory we used acoustic.pany called mix a mate they bring thr sand and cement and mix what ever quantity you need its cheaper than buying a cube mix and wasting some,we needed 2 1/4 tonnes of concrete an ordinary mixer load would have meant a lot of waste, a new greenhouse could be built on the existing walls  try Crittall greenhouses 
Title: Re: Laying Concrete
Post by: snowdrops on June 05, 2020, 08:42
the old greenhouse, is built on brick walls, so the only part that would need to be shuttered would be where the doorway is.   He would need to take the sliding door off, as it would be in the way.  I think it measures about 10 x 8 ft, which at say 4 inches would be a metre of concrete.    My idea is that when the floor is done, all the old can be removed and then consider what to replace it with.   2 side of the walls, are my garage !!
If I try to break the existing up, how would I do that, would I need to use a pneumatic drill.  Thanks folk, Mrs B

Dear Mrs B, on another thread you mentioned your new DIY mad neighbour, I would embrace the fact he likes doing stuff & subtly start mentioning the jobs you are having trouble getting sorted. Start with the outside littler jobs & see if he passes muster, you can then offer to pay him, win win situation & then you might not feel so bad when heís ticking his jobs of his(wifeís lol) list. Plus Iím sure being in your mums old house hasnít helped how you feel even though I know you were relieved it finally all came good  :) Remember the phrase slowly,slowly catches monkey  :lol:
Title: Re: Laying Concrete
Post by: Hause on June 23, 2020, 16:27
I was wondering if you could just cover the concrete surface with sand and lay the new concrete over? We have a concrete surface in a very bad condition in the balcony of our flat in Greece (https://tranio.com/greece/apartments/) but laying a thick layer is out of question since there could be some problems about the balance and leveling. The place is very old so I just don't wanna destroy it..
Title: Re: Laying Concrete
Post by: jezza on June 26, 2020, 20:02
Hello as Snowdrops mentioned you have a DIY mad neighbour and your a member of the WI , may be a Victoria sponge and a glass of carrot wine (not to big a glass)  for him and mention to his wife about the WI she might want to join  jezza