Find a Roofer or Roofers in hampshire based in aldershot, andover, basingstoke, brockenhurst,
eastleigh, fareham, farnborough, lyndhurst, portsmouth,romsey, southampton and winchester. |
|
Flashing
Mortar flashing
Triangular fillets of cement mortar can crumble and allow water to penetrate. Gaps
may appear where the flashing has come away from the brickwork. Use a cold chisel
and club hammer to remove the old mortar. Repair the defective area with a 1 : 3,
cement ; sand mix, adding a little PVA adhesive to help it bond to the remaining
surface. This will give a satisfactory seal, but for a more permanent seal use bituminous
mastic. This can be applied directly from the tin using a builder's trowel or can
be applied with an applicator gun.
Displaced Flashing
If the section of flashing has come away, usually at the top, it can be easily repaired.
Remove any crumbling mortar and clean the area with a brush. Tap the flashing back
into position with a hammer. Use small strips as wedges to help hold the flashing
in position. Repair the area with a 1 : 4, cement ; sand mix, adding a little PVA
adhesive to help it bond to the remaining surface. If any of the surrounding brickwork
needs re-pointing complete that task at the same time.
Corroded or torn flashing
If the flashing is torn or badly corroded then it has lost its value for weatherproofing.
Remove it but leave the soakers in place. Soakers are separate small pieces of lead
or zinc that are used to weather between the wall and the roof covering. The size
of the soakers will vary according to the type of tile or slate used on the roof.
Replace the flashing with a section of flashing strip, moulding it or using a roller
to position it. It is not necessary to cut the strip into steps, unless required
for the sake of appearance. It is also unnecessary to insert the strip into the
mortar joints.
Replacement flashing strips
Metal can be difficult to work with, but can be purchased in small rolls often supplied
with a small tin of primer to help the bonding between the strip and the tiles or
brickwork. Some strips purchased are self-adhesive and come with a backing paper,
which is removed when the sections are in position. There are lead or aluminium
finishes available. If you are using screws or nails, it is important to use those
made from brass, copper or stainless steel, so they will last for a longer period
of time.
Replacing the chimney flashing
Check for evidence inside the home around the chimney breast walls or on the upper
floor ceiling below the chimney stack for signs of dampness. Dampness in these locations
could mean the flashing is worn and needs attention.
Chimney flashing is quite difficult to repair/replace as it is fitted in four sections.
The slanted sides need stepped flashing, while the top needs a back gutter and the
bottom requires an apron.
- Apron flashing
The apron lies at the foot of the stack and should be the first section to be replaced.
It is made in one piece and secured with lead tacks to the top of the tiles.
- Stepped flashing
The stepped flashing is used on both sides of the stack. The sections are tucked
into the mortar horizontally between the brickwork at the base of the stack, where
they cover the soakers. Soakers are separate small pieces of lead or zinc that are
used to weather between the wall and the roof covering. The size of the soakers
will vary according to the type of tile or slate used on the roof.
If the old flashing sections have been removed, then the tiles on both sides have
been removed first to allow access to the stepped flashing. To replace this section,
lay it underneath the tiles on the side of the stack but over the front apron. Mark
its position against the brickwork and mark on the mortar joints. Fitting new lead
stepped flashing will give long-lasting waterproofing as well as the most attractive
finish to the roof. Point all flashing with a sealant. Repeat the procedure on the
opposite side of the stack.
- Gutter flashing
The final section to be fitted is the gutter flashing at the top end. This is normally
one piece that sits over the end of the step flashing.
|