East Sussex · England
External & façade joints in Denton, East Sussex
Sealing brickwork movement joints, render, cladding and façade joints in Denton, with a one-year guarantee on every job. Ask us for a quote.
- Rigid filler in a joint that should flex
- Water getting into walls through failed joints
- Gaps where render, brick and frames meet
External mastic in Denton, done properly
Short cuts in external joints show up within a season or two. New sealant over old, joints packed with mortar and beads with no backing all tend to fail early. We take the old material out and do it properly. We work on concrete & block, copings & trims and render & cladding joints, and people most often call us about damp patches traced to an open external joint and joints where the bead has come unstuck.
Outbuildings, garages and conservatories around homes in places like Denton add more joints to look after. Leaks usually start at a gutter end, a garage door frame or where an extension meets the house.
Whatever the size of the job, it’s backed by our one-year guarantee.
- Place
- Denton (BN9)
- Region
- East Sussex
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before we start
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What the job involves on each surface
Cladding and façade panels
Cladding and façade panels are generally separated by sealed joints. We reseal them with a sealant suited to the panel material.
Brickwork movement joints
Clay brickwork grows slightly over its life and moves with the weather. That movement goes into the joint, so the sealant in it must stay soft and stretchy.
Looking after it afterwards
Good habits help new joints last longer. Our tips:
- Look over the joints every year, ideally after winter
- Get split or bare joints resealed while the damage is small
- Never let anyone fill a movement joint with mortar
- Check the sealant is paintable before painting near it
Do not let soil, plants or ivy build up against the new joints. Damp material against the sealant shortens its life.
An open movement joint lets rain into the wall every time it pours. That can lead to damp patches, staining and frost damage which cost more to put right than the joint.
Also near Denton
Also in Denton
What affects the cost of external mastic
Every job gets its own quote. These are the things that affect it:
- How easy the joints are to reach
- Any working-time requirements on site
- The product the joint needs
- The number and length of the joints
We don’t show prices on the website, because the cost depends so much on the job itself. For a quick quote, please ring 0345 464 0079 or send us an email and we’ll talk you through it.
What we need to know
Photos help, but a description is a good start. Try to tell us:
- Whether it’s a home or a business
- The address or postcode of the job
- How many joints, rooms or windows are involved
- Access, such as stairs, a lift or height
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we will explain what’s involved and give you a clear price.
For landlords and businesses
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. We can quote for more than one property at once.
What we do, step by step
Every visit runs the same way: we look at the joints together, mask and protect the surrounding surfaces, do the work and tidy away. It usually takes a few hours to a few days, depending on the length of joint and the access. Parking around Denton is usually easier than in a town centre, but mention any lanes, gates or long drives. For outside work, side access and the height of the joints help us plan.
- We start by walking round the building and agreeing the joints and the access.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
How to prepare
- Tell us about any water getting in
- Clear items away from the joints we’re working on
- Mention any parking rules near the property
Get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is.
Related advice
Denton: your questions answered
Will you come out to Denton?
Yes, we do. Our work covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Does the coastal weather in Denton affect outside sealant?
Near the coast, wind-driven rain and, nearer the shore, salt air make outside sealant work harder. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
What do you put in the joint?
Each joint gets the product that suits it. Movement, water and weather all affect the choice.
What’s an expansion joint in brickwork?
A vertical gap in a long brick wall is usually a movement joint. It gives the wall room to move, and it should be sealed with a flexible sealant.
Where is Mr Mastic based?
We are based in Crawley, and we cover South East England, London and all of Scotland.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
How long before the joint can be used?
Many sealants skin over quickly but take longer to cure fully. We’ll give you the cure time for the product we used.
How long will you be here?
Typically it takes anything from a few hours to several days, depending on the building. Bigger jobs take longer.
Can I do it myself?
If you’ve already had a go yourself, that’s fine. We cut it out and start again.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
What we’re called out for in Denton
Buildings move more than people expect. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. The sealant in the movement joints takes that strain.
Look out for these signs:
- Old sealant gone brittle and cracked
- Movement joints with cracked, split or missing sealant
- Failed seals between different materials
- Rigid filler in a joint that should flex
If you live in an older home near Church of St Leonard, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Comparing quotes
- Whether VAT is included
- Whether they seal over old material or remove it
- Whether you can choose the colour
- Who turns up on the day
Denton buildings and the weather
Denton is close to the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. Both are hard on movement joints and outside wall joints, which can dry out and crack sooner where a building faces the weather. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For site and facilities teams at buildings such as Denton Community Primary School and Nursery, larger buildings have long runs of movement joint that eventually need resealing. For landlords with property near Newhaven Town station, split movement joints are easy to miss on a rental until damp shows inside.
Denton is about 1 mile north-east of Newhaven, in East Sussex. Wherever you are in the BN9 postcode area, we cover external mastic for homes and businesses. Our East Sussex coverage runs to 289 places, Denton among them. You can also see our page for Brighton, about 9 miles away.
Here we cover the BN9 postcode area for external mastic. You will find streets such as New Road, Avis Road and Hill Road, and we cover them all. With the A26 and A259 close by, Denton is easy for our applicators to reach. Close by, we work in South Heighton (1 mile north), Piddinghoe (1 mile west), Rodmell (3 miles north-west), Telscombe (3 miles west) and Firle (3 miles north). Within a short drive, we also cover Eastbourne (10 miles east), Seaford (3 miles south-east), Lewes (6 miles north-west), Hailsham (10 miles north-east), Uckfield (12 miles north) and Polegate (8 miles east).
Near you in Denton
Locally, jobs take us to homes and businesses close to Flying Fish pub, Castle Hill and UTC@Harbourside and the streets around them. The nearest railway station is Newhaven Town station, roughly 0.6 miles south of the centre. Other landmarks nearby include Arlington Castle (4.8 miles east) and Planet Earth Museum (within half a mile west). For a walk, there’s Southerham Farm and Itford Hill.