How-to Guide tooLS you wiLL need MAteRiALS you wiLL ... - Jewson

PREPARATION
• First, decide what you want to use the loft for
as this will determine what kind of insulation
you will need.
• The simplest way of insulating is by rolling out a
double layer of insulation blanket between the
joists then cross-wise over them.
• If you plan to use the loft for storage, then you
will need strong boarding, making sure each
piece is big enough to cover at least three joists
for stability
• Next, measure your loft. Check the space
between joists and buy insulation at the
appropriate width and length.
• Make sure you’re fully protected with overalls,
mask and gloves. Insulation can be irritating to
the skin and its fibres must not be inhaled.
• Check that your work area is properly lit
• Ensure all other work to the loft is complete and
safe (such as plumbing and wiring).
• If your loft isn’t fully boarded, make sure you
tread carefully, as the spaces between the joists
won’t hold your weight. This will avoid damage
to the ceiling below and injury to you.
DOING THE JOB
ALTERNATIVE MATERIALS
• First, check that you won’t be covering any
electrical wires, as this can cause overheating.
• Fasten any wires to the sides of joists with the
cable clips.
• If there are any downlights inset into the ceiling
of the room below, make sure you fit downlight
heat diffusers to these before laying the insulation
– again to avoid overheating.
• Next, unroll the insulation blanket from the eaves
to the centre making sure it completely fills the
space between the joists. Leave a gap at the very
edge of the eaves to ensure natural ventilation
and eliminate condensation.
• Roll out to the centre, then cut and repeat from
the other end, making sure the ends butt snugly
against each other.
• Once this layer is complete, repeat at 90°
from the previous layer, going perpendicular
to the direction of the joists. Do not compress
either layer, as this will compromise its thermal
performance
If the spaces between your joists are not uniform,
then a roll of insulation blanket may not be
appropriate. In these cases, it may preferable to
empty sacks of loose-lay material into the spaces
between joists.
Before doing this, make sure none of the
material can disappear down the cavity wall
by blocking the eaves with lengths of timber
between the joists. As above, be careful not
to block this area completely, so as to avoid
condensation. Also, seal any holes in the ceiling,
such as those through which pipes or wiring are
fed, with expanding foam filler.
Next, empty sacks of loose-lay into the spaces.
Use the edge of a piece of wood to smooth and
level off the layer. Once this is laid, be aware
that every time you open or close the loft the
draught can blow the material about, so a layer
of blanket insulation or board insulation over the
top is advisable.
LAYER 1
JOISTS
LAYER 1
JOISTS
LAYER 2
LAYER 1
JOISTS
LAYER 1
JOISTS
LAYER 1
• Insulate over the cold-water tank, but not under it.
If it’s too well insulated from heat below it
may freeze (see other essentials below for
more information)