Construction and new-build mastic

What construction and new-build mastic covers

On a building project, mastic comes near the end of the trade sequence and gets squeezed whenever earlier trades run late. The package then has to move quickly without cutting corners, because poorly prepared joints come back later as snags, leaks or callbacks. We work as the mastic subcontractor for main contractors and developers on new-build and refurbishment schemes. That covers external window and door perimeters, movement joints, internal decorators’ caulk where specified, sanitary joints in bathrooms and washrooms, and kitchen worktops. We read the specification and the sealant schedule, check joint sizes against the product’s movement capability, and flag anything that doesn’t add up before we start. Our applicators are CSCS-carded, and we are CHAS accredited and a Constructionline member. We can follow your sequence plot by plot or floor by floor, and return for snagging before handover.

We work across South East England, Greater London and all of Scotland. Our workmanship carries a 12-month guarantee, we’re CHAS accredited and a Constructionline member, and our applicators hold CSCS cards.

Problems we put right

• A mastic package that has to keep pace with the programme
• Snag lists full of missed, smeared or gapped joints
• Sealant applied onto damp, dusty or unprimed surfaces by other trades
• Joint sizes that don’t suit the specified sealant
• Plots or floors that must be ready for handover inspections
• Site paperwork needed before applicators can start

Joints and areas we seal

• Window and door perimeters
• Internal decorators’ caulk
• Sanitary and kitchen joints
• Brick and block movement joints
• Cladding and panel joints
• Floor and skirting junctions

Why it’s worth doing now

On a new building, sealant is one of the last trades and one of the most visible. Joints that are sealed out of sequence, onto damp or dusty faces or at the wrong depth come back as snags, defects and call-backs after handover. A dedicated mastic package keeps it on programme and to the specification.

What affects the quote

We don’t publish set prices, because no two buildings are the same. Send details and we’ll give you a fixed quote before we start. The main things that affect it are:

• How many metres of joint there are, and how many areas, elevations or sites
• How much failed sealant has to come out, and how hard it is
• Joint size, depth and whether backing rod or primer is needed
• Access: height, scaffold or MEWP access arranged by others, occupied areas
• The product the joint needs (and colour, where it matters)
• Programme, phasing and site requirements such as permits and inductions

What a good quote includes

• All failed sealant removed, never sealed over
• The product named for each joint type
• What the 12-month guarantee covers
• When each area can be used again
• Who is doing the work, their CSCS cards and the insurance in place
• What site paperwork and records are included

Aftercare

Hand over a simple record of which products went where. Brief the client’s maintenance team on cure times, and on not painting over sealants that aren’t paintable. Snags raised during the defects period should be reported quickly so the joint can be looked at before anything else is damaged.