Installation Guide

20
JG Speedfit
Plumbing and Heating
Traditional joists
Instructions on the drilling of joists is given in the
Building Regulations Approved Document A, and
summarised as follows:
1. Holes should be no greater than 0.25 of the
depth of the joist
2. Holes should be drilled at the neutral axis
3. Holes should not be less than 3 diameters
(centre to centre) apart
4. Holes should be located between 0.25 and
0.4 times the span from the support
Timber ‘I Beam’ joists
Several types of joists are available and Speedfit
recommends that specific manufacturers details are
consulted. However, the following can be used for
general guidance:
 Holes may be located vertically anywhere in the web,
but leave 3mm web at the top and/or bottom of hole.
Do not cut into joist flanges when cutting the web.
 If more than one hole is to be cut in the web, the
distance between the edges of the holes must be at
least 2x diameter of the largest hole.
 Generally joists are manufactured with 38mm
perforated knockouts in the web at approximately
300mm centres along the length of the joist.
Cross web joists
Unlike 'I beam' joists, pipe
can be cabled anywhere
within the open Web as
no drilling is required.
However, the top and
bottom flanges must not
be notched. Avoid damaging the outside diameter of the
pipe as you cable through the metal cross web members.
Timber framed construction
Speedfit is well suited for timber frame construction.
Ensure that the structural integrity is not compromised
when installing the pipework. If the pipe passes through
an external wall, care must be taken not to damage the
vapour barrier and should be installed on the inside of
the thermal insulation layer.
If this is not possible, the use of conduit should be
specified at the design stage.
Steel framed construction
Speedfit is well suited for steel frame construction
and care should be taken when installing the pipework.
All runs should be installed through preformed hole in
the structure and protected by a rubber or plastic grommet.
Where clipping of pipework is restricted, cable ties may
be used to secure the pipe. As with all installations,
make sure that any pipework passing through walls
and floors does not aect the fire resistant properties
of the structure.
Dry lined walls
Speedfit pipework can be easily cabled through studwork
and within wall systems as well as behind ‘dot and dab’
plasterboard installations. Speedfit 10mm Barrier Pipe is
most commonly used to feed radiators. If incorporating
fittings in this way, collet covers or collet clips must be
used with the Standard Range of Fittings.
Wet plaster
To prevent surface damage to the plaster caused by
expansion and contraction of Speedfit Pipes, it is
important to ensure that all Speedfit Pipework is
channelled into the wall and protected with appropriate
sleeving. Alternatively, the pipework can be surface
mounted and boxed in if required for aesthetic appearance.
Laying of pipe in concrete
and masonry
Speedfit pipe and fittings can be laid in concrete and
masonry providing they are installed in conduit pipe
with access boxes for the fittings. As stated in Water
Regulation Schedule 2.7 and BS 8000: Part 15, fittings
and pipe should be removable for possible replacement.
Insulation is also recommended to protect against heat
loss and the eects of frost. Speedfit Conduit Pipe is in
either 15mm or 22mm in coil
lengths of 25m or 50m. The
flexible convoluted pipe has
an outside diameter of 24mm
and 30mm.
Max. dia. of holes = 0.25D
Min 3 x hole dia.
0.25 S 0.4 S
D
Joist
Clips
Speedfit pipe