Weatherproofing & External Joints
External Sealant
External mastic for façades, brick, render, cladding and window perimeters. Old sealant is removed and the cause of any water ingress is assessed before resealing.
External Work We Carry Out
- External window and door perimeters
- Brick and render interface joints
- Cladding and panel joints
- Thresholds and sills
- Weather-sealing around suitable penetrations
- UV and weather exposure considered
- Old sealant removed before resealing
- Cause of water ingress assessed
Common Problems
Cracked or missing façade mastic
Sun, rain and frost break down external sealant over time. We remove and reseal with a product suited to the exposure.
Water ingress around window frames
Failed perimeter seals can be one cause of water entry. We reseal the frame properly and will flag other likely causes if we see them.
Cladding panel leaks
Movement and UV cause cladding joint sealant to fail. We strip and reseal with the right system.
Gaps around external penetrations
Pipes and cables entering the building need weather-sealing. This is weather-sealing, not firestopping.
What to Send for a Quote
- External photos of the affected joints
- Substrate types (brick, render, cladding, timber)
- Approximate linear metres
- Height or access constraints
- Any internal water ingress or staining
Our Process
Inspect and photograph
We identify which joints have failed, why they have failed and the right access approach.
Choose the right sealant
Selection depends on the substrate, joint size, movement, UV exposure and manufacturer guidance.
Remove and clean
Old sealant is fully removed and surfaces are cleaned and primed where needed.
Seal and finish
The new sealant is applied and tooled to give a neat, weathertight bead.
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Common Questions
Can you reseal around existing windows?
Yes. We reseal the perimeter mastic around existing UPVC, aluminium and timber window and door frames without removing the frame.
Can failed mastic cause water ingress?
It can be a route for water. Failed perimeter or façade sealant can let water in at that point, but ingress can also come from failed pointing, roof issues, damaged frames or blocked gutters. We assess the cause before quoting.
Can you work at height on external walls?
For high or difficult-to-reach work we can use rope access, MEWP or scaffolding. See our Rope Access Mastic service for suitable commercial high-level work.
How long does external mastic last?
Service life varies with sealant type, joint design, UV exposure, building orientation and maintenance. We inspect the joint and recommend a replacement product for the specific situation.
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Mastic and sealant work for main contractors, facilities managers and developers across Liverpool and the North West. Glazing perimeters, curtain wall interfaces, cladding joints and expansion joints.
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View ServiceGet a Quote
Send photos and your postcode by WhatsApp, email or the contact form and we will come back with a price.
07538 385459