technique may be used where it is not possible to lay the pipes
above the joists, e.g., where floor levels are fixed and cannot
be altered. This method is more labour intensive but the end
result is the same as the preferred pipes above
method. The joists are notched to allow the pipes to pass between
the spaces. The space around the pipe is infilled with a dry
sand/cement mix which provides the thermal mass needed to conduct
the heat through the floor. Insulation should be a minimum 75mm
note: If using this method you should check with
your architect or structural engineer as to the suitability
of this technique. We cannot accept responsibility for loss
or damage to property due to the increased weight loading and
stresses on the joists due to notching.
Rigid insulation boards must be used for ground floors, recommended
at least 75mm fitted hard up against the under side of the sub-base.
Mineral wool or similar can be used for upper floors, but all
through draughts between the joists must be eliminated.
- Underfloor heating installed between the joists
timber floor construction diagram