Extension lead connections

Statement: "There are repairable defects in the bed joint above the lead strip between the facade and the roof of the extension." In that case, we recommend maintaining the current situation and repairing the bed joint. Where necessary, deepen the joint sufficiently, remove debris and loose material, and repair the joint in accordance with the existing work.

Statement: "The lead flashing must be (partially) replaced." Replacing such a lead flashing is not easy! In masonry, the best solution is to remove strips of brick so that the flashing can be installed in the cavity against the inner leaf. Another solution could be to grind the flashing at least 4 cm deep into a joint. If installing under a window frame, a professional is recommended.

Statement: "The lead flashing needs to be (partially) repaired ." This can be done by patching cracks in the flashing with self-adhesive bitumen tape, available at any hardware store. As long as repairs are possible, we recommend postponing replacement.

• Simply clamping the foot lead and closing a joint is not a proper repair.
• The lead must normally be fitted through the cavity up to the inner leaf.
• Replacing lead flashing isn't easy! Strips of masonry must be removed to properly repair it.

Statement: "The lead flashing (the part visible from the brickwork) is too high and hangs (or rests) too much on the horizontal roof surface." Due to creep and capillary action of water remaining on the roof, there is an increased risk of water ingress and/or leakage in the cavity or at this connection. Correcting this is easily achieved by shortening the height of this lead flashing.

• Lead can easily be cut and 'torn off' with a utility knife.
• Always place a piece of board under the lead to be cut, this prevents you from accidentally cutting the bitumen.

Statement: "The lead strips (the part visible from the brickwork) are too long." The strips may have a maximum length of 1 meter and must overlap by at least 8 cm. The materials are subject to weathering. Because they are too long, there is insufficient space to accommodate the shrinkage or expansion. This causes the material to crack more quickly, leading to defects. Now that the lead has been applied in this way, there's little you can do other than accept it. This does shorten the material's lifespan, and the lead will need to be replaced sooner than usual.

Outside becomes inside > then repair is necessary

There's a connection between the roof of the extension and the facade of the house. This connection is usually made waterproof with a lead strip (flood seal). This lead runs through the cavity of the facade and is attached to the inner leaf. Rainwater absorbed by the facade and seeping down is thus forced out. If the bitumen is glued down (or a compression strip is used), this water can get behind the bitumen and cause leaks or other defects in the house. The flood seal, as described above, must then still be installed.

• Replacing lead flashing isn't easy! The best solution is to remove strips of masonry to make a proper repair.
• Another acceptable solution is to grind the joint deeply (6 cm) and apply the lead to the maximum depth, after which it can be filled in.
• Simply clamping the foot lead and closing a joint is not a proper repair.
• Applying a lead strip with a clamping strip is also not a proper repair.

Outside stays outside > recovery not necessary

There's a connection between the roof of the extension and the facade of the house. This connection is usually made waterproof with a lead strip (foot lead). This lead runs through the cavity of the facade and is attached to the inner leaf. Rainwater absorbed by the facade and seeping down is thus forced out. In this case, a compression strip (or other form of seal) has been used, and the intended drainage will therefore not function optimally.

• If the extension or conservatory is considered an outdoor space, no improvement is necessary. The current situation can remain as it is. However, it must be taken into account that moisture (absorbed by the facade) at this connection will not be directed outside and can enter the room. Technically, this is not a defect that could cause damage.
• If outside remains outside, it is not necessary to apply a lead flashing.
• If outside becomes inside, good drainage is essential. For brick walls, the lead flashing is often recessed approximately 4 cm. For cavity walls, the best solution is to attach the lead flashing to the inner wall.
• The exposed portion of the lead on the outside must not exceed 80 mm in width (height). Otherwise, the creep effect (with the risk of cracking and water ingress) will be too great.
• A strip of foot lead may be a maximum of 1 m long and must overlap by at least 8 cm.

The cost of a building inspection (for homes up to 1000 m³) is only €489 including VAT. We'll conduct a comprehensive building inspection , and you'll receive a building report . Do you have any questions? Call us during office hours (Monday to Friday, 9:00 AM to 5:00 PM) at 085-0653675 . We're happy to help and can schedule an appointment with a qualified inspector right away, if desired!

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