Building in cold
weather - best practice guidance
Take care when working with concrete in cold weather. If
concrete cools too much below freezing it will become unfit for
use. This is because the water in the concrete freezes and expands.
This causes micro-cracking making it weak and not usable.
To avoid this happening the concrete needs to gain an initial
strength while being kept warm. The concrete needs to be maintained
at or above 5oc for the first 48 hours.
A concrete plant may be able to supply heated concrete. Ideally
this should be supplied at a temperature of at least
10oc Check that when the concrete arrives on site the
temperature is still above 5oc. The surfaces to be
concreted must be free of ice and frost. The concrete needs to be
kept warm after it has been placed.
Mineral wool quilts or foam mats are good at helping to keep the
exposed concrete warm. These must be used when the temperature
drops below freezing. Polythene sheets do not have any
insulation value, but they create an air gap that can help maintain
the concrete temperature, and these are normally adequate when
placing trench foundations.
It is also possible to speed up the hardening time of the
concrete, and this will reduce the amount of time the concrete
needs to be kept warm. This can be achieved by increasing the
amount of cement in the concrete, increasing the strength of the
concrete, or by using admixtures.
More information on concreting in cold weather can be found on
the Concrete Society web-site at www.concrete.org.uk
Bricklaying should not be carried out when the temperature drops
below 3oc or when frost is imminent. When starting work
after an overnight frost, check that the partially completed
brickwork is above freezing point. If the brickwork is frozen the
mortar bed will freeze and no bond will form.
Mortar can be made more frost resistant by increasing its
strength. The use of an accelerator, such as anti-freeze is not
recommended. This is because the amount of cement relative to the
amount of brickwork is relatively small, and the amount of heat
generated is low and is not enough to keep the brickwork warm. Air
entrained mortars can give some frost resistance, but always follow
the manufacturers instructions on use.
Excess of water in materials is a problem when working in cold
weather. Keep bricks covered to protect from rain or snow, and
stacked clear of ground water. Keep sand and lime dry.
Cover the top of the wall to give protection in cold weather.
Hessian can be used to insulate, but this must be kept dry by a
polythene sheet. If Hessian becomes wet it can cause staining and
efflorescence. Allow the brickwork to dry out by leaving an air gap
between the cover and the wall. Secure the cover to prevent them
being dislodged by wind.
More information on bricklaying in cold weather can be found on
the Brick Development Association web-site at www.brick.org.uk
Building regulations are
still a must says LABC
The recent Government announcement to relax planning permission
laws for home and business owners to extend their properties does
not remove the need for compliance with building regulations says
Paul Everall, Chief Executive of LABC said "Whilst we welcome
the Government's move to boost the economy through a programme of
house building and the removal of planning red tape, we stress that
this only addresses part of the problem and more needs to be done
to improve the mortgage market so that people are able to buy."
Paul continued, "Changes in planning laws have not removed the
requirement for property owners to follow building regulations
which ensure buildings are safe and sustainable. Building
regulations are separate from planning permission and our primary
concern is that safety in and around buildings is maintained"
"There still needs to be an awareness that Building Regulations
will still apply to many of these extensions where the property
owner is looking to make structural changes to an existing
property. A building notice will need to be submitted to the local
building control department for approval to ensure building
regulations are met. Our local authority building control teams are
used to working quickly with developers and homeowners to help them
through this process and ensure that construction work leads to
healthy, safe and sustainable buildings.
Paul concluded, "The removal of planning law could impact the
sustainability agenda as new buildings must be sustainable and
energy efficient and the Government must not weaken in its desire
to be the greenest Government ever."
Did you know you could email your building control application
form and any plans to firstname.lastname@example.org?
(Emails with attachments larger than 4MB should be sent to email@example.com).
Just click on the 'Email Form' button at the bottom of the PDF application form
to send. An invoice will then be sent to you the following
week which can be conveniently paid for by cash, cheque, BACS, card
or via the website (full details of how to pay will be enclosed
with your invoice). This process ensures we can start looking
at your application as soon as possible and will not delay the
registration of your application in any way.
Changes to the
ownership of some types of private sewers
Changes are being made to the
ownership of some sewers and drains that are currently the
responsibility of the householder. From 1st October 2011, ownership
of these sewers and lateral drains transfered to Severn Trent
Water. This however does not affect all sewers and drains.
For further information on which
sewers and drains will be affected by this transfer of ownership
please visit their website
for further information.