Crosspost construction mastic
Construction mastic in Crosspost, backed by over 20 years in commercial sealing. Fully insured and CHAS accredited.
- Missed perimeter joints on a new elevation
- Sealant knocked or painted over by other trades
- Existing joints on a refurb that need cutting out and resealing
Construction mastic for Crosspost sites
Share the site address and what’s failing, and we’ll reply with a fixed quote or arrange a visit.
Doing it in-house
General builders and handymen seal joints, but it isn’t their main trade. A specialist prepares properly, controls joint depth and picks a product with the right movement class, which is what makes a joint last.
For a quick touch-up, site staff may be fine, but larger jobs are different: a specialist works through quantities efficiently, leaves a consistent finish and backs it with a 12-month guarantee.
Construction mastic in Crosspost
We work to the specification and the programme, not to habit. Where the specification names a product, we use it, and if an alternative is proposed, it goes to you for acceptance first. Backing, primer and depth follow what the sealant maker sets out so the detail on the drawing is what ends up on site. We work on internal decorators’ caulk, floor and skirting junctions and brick and block movement joints, and the usual reasons a site gets in touch are existing joints on a refurb that need cutting out and resealing and early adhesion failures on new external joints. A single leaking joint is often how a building in Crosspost first comes to us: we check the joints around it and give you an honest view of what needs doing now and what can wait.
In the countryside around places like Crosspost, conversion schemes put new frames into old stone, flint, brick or timber. A product that grips an irregular face, with a colour that suits the building’s character, is usually what’s needed.
What our 12-month guarantee covers is the way we did the job: the preparation, the sealing and the tooling. Damage, later alterations by others and movement beyond what the joint was designed for sit outside it.
- Location
- Crosspost (RH17)
- Region
- West Sussex
- Cover
- 12 months on every job
- Quote
- Fixed quote, scope in writing
- Phone
- 01277 525 020
- Last updated
- 3 November 2026
Common problems we fix in Crosspost
On a live site, contamination is the biggest threat to a new joint. Dust, film adhesive, damp and grease on the joint faces prevent a proper bond, so preparation matters as much here as on a reseal.
Typical triggers for a call:
- Oversized or tapered gaps around new frames
- A mastic package split between trades with no clear owner
- Sanitary sealant damaged by following trades
- Caulk cracking where joints are moving more than expected
When a school such as Bolney CofE Primary School is extended or refurbished, the mastic package is often squeezed into the holidays.
What to look for in a quote
- Their approach to joint depth and backing
- Their plan for phasing and protecting the area
- Which product they’ll use, and why it suits the joint
- Their public liability cover
Our process
In a busy building, the work is phased so only one area is out of use at a time. Each section is protected, cleaned back and sealed before the next one starts. For work around Crosspost, we aim to finish in one visit, so we ask for photos and rough sizes first. That way the right products come on the day.
- We walk the site or review drawings to understand the package.
- A fixed quote sets out scope, products and phasing.
- Site paperwork is confirmed and our CSCS-carded applicators are inducted.
- We seal plot by plot or floor by floor in line with the programme.
- Problems we find, such as oversized gaps, are raised straight away.
- Final snagging is completed and the 12-month guarantee applies.
What we need from you
- Confirm the product named in the specification
- Tell us your opening times and when work is allowed
- Arrange parking or a loading space
Get a fixed quote
Every job follows the same four steps: send details, get a quote, we seal, guaranteed. To take the first step, give us a call on 01277 525 020 or email the details over.
Related advice
Crosspost: questions and answers
Is Crosspost too small for you to travel to?
Not at all. Crosspost is within our area. Our area covers London and the South East counties. We plan jobs in smaller places so return trips are kept to a minimum.
Does your area include sites such as Crosspot Industrial Estate, near Crosspost?
Yes, sites like Crosspot Industrial Estate are within our area, along with the rest of Crosspost. To start, just ring 01277 525 020 or send photos by email with the unit, the joints involved and your access times.
Can you handle several sites?
Yes. We take on portfolio and planned maintenance work, with each site phased to suit its occupants.
What if there’s asbestos in the old mastic?
Some older mastics, especially in pre-2000 buildings, can contain asbestos. We check the asbestos register before cutting out old sealant in an older building, and if asbestos is suspected, work stops until it’s tested. Removing asbestos is a job for asbestos specialists, not us.
Can the building stay open while you work?
In the majority of cases, yes. We phase the work so most of the building stays in use.
Do you guarantee new-build sealant work?
The work is guaranteed for 12 months. Protecting sealed areas from following trades helps avoid damage.
Can you follow the specification on our project?
Yes. Send it with your enquiry, and we will price the work to it.
New build and refits around Crosspost
A 2-mile radius around Crosspost takes in a number of hotels. When hotels extend or refit, the work is usually squeezed between peak periods, mastic included. Crosspost is about 36 miles from central London. Building activity in the commuter belt runs from new flats near stations to business park refurbishments, so mastic packages have to keep pace with busy programmes.
New wings at hospitals like The Dene Hospital (2.5 miles south-east of Crosspost) bring long runs of window and panel joints to seal. For a contractor at a hotel such as The Castle Hotel, which lies south-east of Crosspost, the mastic often has to be finished before a reopening date.
Crosspost is about 4 miles north-west of Burgess Hill, in West Sussex. Any commercial site in Crosspost is covered, for single jobs and planned programmes alike. 373 places across West Sussex fall within our area, including Crosspost. For work in that direction, see our Brighton page, about 11 miles away.
Work on mastic packages is covered throughout RH17. Buildings on Cowfold Road and Chapel Road are within our area. Close to Crosspost, our area also takes in Bolney (1 mile north-east), Twineham Green (1 mile south), Twineham (2 miles south), Wineham (2 miles south-west) and Kent Street (2 miles west). A short drive away, we cover Crawley (9 miles north), Horsham (7 miles north-west), Worthing (14 miles south-west), Haywards Heath (5 miles east), Burgess Hill (4 miles south-east) and East Grinstead (13 miles north-east).
Near you in Crosspost
The nearest railway station is Wivelsfield station, roughly 4.2 miles east of the centre. Well-known places in the area include The Dene Hospital (2.5 miles south-east) and Cuckfield Museum (3.2 miles north-east). Not far away are Blunts Wood and Paiges Meadow.
Owners, agents and contractors
When you manage a building on behalf of an owner, you need clear quotes and clear reporting. We quote a fixed sum, confirm the scope and walk the finished work with you or your representative.
For main contractors, we work as the sealant subcontractor. We work to your programme, your specification and your site rules, and our applicators hold CSCS cards.
What sealant work can’t fix
Sealant solves a lot, but not everything, and we’re upfront when that’s the case. These need a different solution:
- Defective windows, doors or glazing units (the supplier or installer’s job)
- Specifying the product where the designer hasn’t
- Deciding which fire-stopping product a penetration needs
Not sure which it is? You can phone 01277 525 020 or use the quote form and we’ll tell you honestly before you book.
What we seal
- Window and door perimeters
- Brick and block movement joints
- Floor and skirting junctions
- Internal decorators’ caulk
- Sanitary and kitchen joints
- Cladding and panel joints
Nearby places to Crosspost
More services for Crosspost
Why it’s worth doing now in Crosspost
Leaving mastic to whichever trade is fitting the element can look cheaper on paper. In practice it often means different standards, gaps in responsibility and snags nobody owns. A single mastic package gives one point of responsibility. Converted and older buildings near places like Crosspost tend to move, and aged sealant cracks. The right product, sized to the joint, copes much better.
We don’t publish prices, because the scope varies so much from one building to the next. For a fixed figure, call for a quote and we’ll price your job on its own details.
Why appoint us
- Our applicators hold CSCS cards
- One number for every site we cover
- Matching to RAL references, product permitting
- Commercial sealant work since 2005
Read our cost guide and our accreditations.