Beam Foundation build

[colin7777]

After many months working through Timber frame companies and foundation options we are very close to making a decision but just looking for some views / clarity as to the foundation / floor insulation.

 

We have to have piles due to being by a river that will have a steel ring beam. it is a small one and three quarter property approx 13 metres by 6 metres and looking to use block and beam.

 

We are not aiming for a highly insulated house, walls have an estimated 0.16 U, and ceiling has an estimated 0.13U. The timber company can supply the floor insulation and have quoted 90mm Kingspan kooltherm K103. Does this seem a sensible thickness to get a balanced U value for the property, would there be any benefit to increasing the thickness for comfort / cost benefit.  The bedrooms are on he ground floor and we have decided not to have UFH .

 

Their diagrams show that the timber frame would be placed on two layer of bricks which I guess takes up the insulation and screed height, I was expecting the timber frame to be fixed directly to the screed / Block and beam. One thing that puzzles me is how everything is going to be held down  if brick is used:

 

Timber Frame

Sole Plate

DPC

Brick

Beam and block

Steel Ring Beam

 

Any ideas, comments, experiences, do's and don't or any views on any aspects welcomed.

 

Colin

 

 

Edited January 16, 2020 by colin7777

[Temp]

We have 80mm PIR in our floor and if building again would fit more, perhaps double. In fact I might consider double Building Regs minimum everywhere.

[Mr Punter]

Floor insulation is simple and cheap to install so you may want to go a bit thicker.  The screed does not need to finish level with the bricks.  You will normally have a 38mm thick sole plate plus the bottom rail of the timber frame so you could go 120mm insulation, 60mm screed and there will still be 46mm of timber at the bottom to fix your plasterboard.

 

The timber frame firm should design the holding down detail.  It could be metal straps fixed to the floor or screws and plugs.  Ask them.

[colin7777]

On 16/01/2020 at 15:36, Mr Punter said:

Floor insulation is simple and cheap to install so you may want to go a bit thicker.  The screed does not need to finish level with the bricks.  You will normally have a 38mm thick sole plate plus the bottom rail of the timber frame so you could go 120mm insulation, 60mm screed and there will still be 46mm of timber at the bottom to fix your plasterboard.

 

The timber frame firm should design the holding down detail.  It could be metal straps fixed to the floor or screws and plugs.  Ask them.

 

Edited January 20, 2020 by colin7777
changed

[colin7777]

Since initial post I have been shown this option where the Block and Beam are mounted within the I section of the Steel Beam, has anyone else built their foundations this way. Anyone see any problems with this method.