Condensate, which can form in chimneys when hot gases impinge on cold
chimney linings, can create two serious problems. The first is the formation of
combustible tars on chimney linings that may cause chimney fires. The second
is the formation of sulphite solutions that can attack chimney mortar which can
lead to leakage, staining and possibly even chimney collapse.
Other reasons for relining chimneys are to seal broken or cracked masonry work
and to improve draft by reducing flue size.
Why Perlite?
Expanded perlite is an ideal material for insulating chimneys as it is inorganic,
does not support combustion, and exhibits excellent thermal insulating
properties over a wide range of temperatures. In addition, it is not affected by
most acids. Perlite chimney insulation may be mixed on-site, but premixed
material is commonly used to ensure consistent quality control. For new
construction, perlite loose fill chimney insulation may be used between the flue
and the body of the chimney.
Reconditioning Chimneys
Pumped chimney lining is often used in the repair or relining of existing
chimneys. In this type of installation, a rubber tube is inserted the length of the
chimney to be relined. The tube is supported and sealed off in the firebox or at
the base of the chimney and the tube is inflated to the desired diameter. Both
round and elliptical tubes are available depending on the configuration of the
chimney. Spacers maintain the tube in position in the chimney. Perlite chimney
lining is pumped into the space between the tube and the inside of the chimney.
When the mix has set for a minimum of 12 hours, the tube is deflated and
withdrawn and the top of the chimney is capped off with mortar. As there are
many variables involved in a proper installation, trained personnel should be
used to prepare mixes and to reline chimneys. In all cases, the procedures and
mix formulations employed should meet applicable building requirements.
New Construction
Lightweight perlite loose fill insulation or a lean mix of expanded perlite and
cement may be used to insulate new masonry chimneys as they are being
constructed. In this type installation, the perlite is poured or pumped between
the flue and the body of the chimney as it is being constructed. This same type
of construction may be employed when metal flues are being used. In addition
RYOLEX® perlite can also be used with other binders in the manufacture of
prefabricated chimney liners.
|
PERLITE CHIMNEY LINING SYSTEMS SOLVE CONDENSATE PROBLEMS IN
OLD AND NEW CHIMNEYS
