I have just had a 4" deep concrete pad poured by a local builder for a hot tub. As the pad will be supporting a hot tub which ways about 1900Kg it needs to be flat and level. The builder was awre that it would be used for a hot tub and as such that it needed to be flat.
Unfortunately it is neither level or more importantly flat. There are variations in level / flatness of as much as 10mm over 2metres making it unsuitabel for a hot tub. If I placed teh tun on this surface I would risk distorting or cracking it ince filled with water. The builder is coming around tomorrow to take a look, but I want to have a good feel of what can be done before he arrives. From what I can see there are 2 choices:-
1.) Self leveling external compound such as Ardex K301 which can be poured thinly.
2.) A thicker layer of screed.
I dont want a thick layer of screed as this will result in the hot tub neing at the wrong level. I am therefore wondering what is the thinest layer of screed that could be used externally that wont break up over time. From what I gather screed is normally around 50mm thick.
I am also wondering if there are any other suitable leveling compounds that are cheaper than Ardex K301 as that is about £60 per bag an I am guesing that woudl require about 3 bags ie about £180 which I think teh builder is not going to swallow - especially as the whole job was only £900.
Would reqlly appreciate some ideas on what is the best long term solution to this.
Thanks
Unfortunately it is neither level or more importantly flat. There are variations in level / flatness of as much as 10mm over 2metres making it unsuitabel for a hot tub. If I placed teh tun on this surface I would risk distorting or cracking it ince filled with water. The builder is coming around tomorrow to take a look, but I want to have a good feel of what can be done before he arrives. From what I can see there are 2 choices:-
1.) Self leveling external compound such as Ardex K301 which can be poured thinly.
2.) A thicker layer of screed.
I dont want a thick layer of screed as this will result in the hot tub neing at the wrong level. I am therefore wondering what is the thinest layer of screed that could be used externally that wont break up over time. From what I gather screed is normally around 50mm thick.
I am also wondering if there are any other suitable leveling compounds that are cheaper than Ardex K301 as that is about £60 per bag an I am guesing that woudl require about 3 bags ie about £180 which I think teh builder is not going to swallow - especially as the whole job was only £900.
Would reqlly appreciate some ideas on what is the best long term solution to this.
Thanks