Extending existing conservatory base/footings

[waynemartin]

Hi,

I have recently had an existing base for a conservatory entended by more than double in size and had a all glass conservatory put up.

I am in the process of putting wooden flooring down but before I do I wanted to know what the best way would be to join the existing base to the extended part? Currently the builder has just concreted up to the existing base leaving a very small gap between the two bases.

Should I make this gap a little bit bigger to maybe 10mm so that I can put an expansion joint in or is that not recommended? Bearing in mind the conservatory is up and I need to deal with the floor situation somehow!!

I would really appreciate some advice here!

Many thanks

Wayne

 

[simonjay]

Hi,

I have recently had an existing base for a conservatory entended by more than double in size and had a all glass conservatory put up.

I am in the process of putting wooden flooring down but before I do I wanted to know what the best way would be to join the existing base to the extended part? Currently the builder has just concreted up to the existing base leaving a very small gap between the two bases.

Should I make this gap a little bit bigger to maybe 10mm so that I can put an expansion joint in or is that not recommended? Bearing in mind the conservatory is up and I need to deal with the floor situation somehow!!

I would really appreciate some advice here!

Many thanks

Wayne

Two things.

1. The DPM under the slabs should have been joined / overlapped - has this been done ?

2. Relative movement between slabs ?
Has the new slab been joined to the old with rebar ? If not cutting slots and inserting resin fixings is possible.
Otherwise you could get some slight movement between the slabs in the future. If its a floating timber floor or boards on battens, you should get away with it. A tiled floor could crack along the joint line.
If glued-down parquet etc, you could get some blocks coming loose.

An expansion joint would not usually be required in a domestic solid floor.
If there is insulation around the perimeter this would allow for some expansion.
Simon.

 

[waynemartin]

Hi Simon,

Thanks for the reply!

The exisisting base did not have a DPM, however it was built approximately 17 years ago and we have lived here for seven years with no damp what so ever! I dont think a rebar was fitted either!

So bearing in mind that I'll be laying wooden flooring, what do you think the best way forward would be?

I forgot to mention that I have two manholes within the new base which now have double sealed internal manhole covers on them.

I was also told by my builder to paint the floor with some damp proof paint. I was also going to be using a damp proof sheet underneath my insulation!!

Cheers

Wayne