Hertfordshire · England
External & façade joints in Appspond, Hertfordshire
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Appspond and across Hertfordshire. Fully insured, ARBOMaster approved and guaranteed for a year.
- Movement joints filled with mortar instead of sealant
- Sealant that has lost its bond to the brick or render
- Weeds or debris growing in open joints
Appspond: your questions answered
Is Appspond in your area for external mastic?
Yes. Our work covers London and the South East, and Appspond is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job.
Is Appspond within the area you cover?
Yes, smaller places are covered as well as towns. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
What do you put in the joint?
Quality sealants from brands including Arbo and Everbuild, picked for each joint. We explain the product when we quote.
What’s an expansion joint in brickwork?
Most straight vertical gaps in brickwork are movement joints. It lets the bricks expand without cracking, and it should be sealed with a flexible sealant.
What does external mastic cost?
The cost depends on the size of the job, access and how much old sealant has to come out. Ask us for a quote.
Are you fully insured?
Yes, we’re fully insured.
What information do you need?
The location, the problem and the rough size of the job. Photos by email help too.
How long should I leave it?
That depends on the sealant used, so please follow the time we give you when we finish.
About our external mastic in Appspond
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, so it bonds to the two sides only and can stretch. If you have leaking joints around cladding and façade panels and damp patches traced to an open external joint, we can help, on brickwork movement joints, copings & trims and façade panels alike.
Outside joints can only be sealed when they’re dry, so work in Appspond is booked around the forecast. Let us know about access to every wall, plus any garages or outbuildings.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Location
- Appspond (AL2)
- Wider area
- Hertfordshire
- Cover
- One year on every job
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Walls and rooflines in Appspond
Historic houses like High Elms Manor (about 2.5 miles south) are a reminder that the area around Appspond has older buildings as well as new. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material. 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.
Historic houses such as High Elms Manor, about 2.5 miles south, show how far back building around Appspond goes, and older homes nearby need a sealant that suits their walls. Rented homes near St Albans Abbey station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Appspond is about 3 miles west of St Albans, in Hertfordshire. Jobs in Appspond get the same care as everywhere else we work: old sealant removed completely, careful preparation and a 12-month guarantee. 381 places in Hertfordshire are on our list, large and small. You can also see our page for London, about 21 miles away.
Postcode districts we cover here for external mastic: AL2. We also cover the places around Appspond: Chiswell Green (1 mile south-east), St Stephens (2 miles east), Waterdale (2 miles south), How Wood (2 miles south-east) and Bricket Wood (2 miles south-east). We also work in nearby towns such as Watford (5 miles south), Hemel Hempstead (3 miles west), Stevenage (15 miles north-east), St Albans (3 miles east), Welwyn Garden City (9 miles north-east) and Harpenden (6 miles north).
What’s near Appspond
In Appspond, that means homes and buildings near Holly Bush Public House and Verulamium Park, among other places. The nearest railway station is St Albans Abbey station, roughly 2.1 miles east of the centre. A little further out are Leavesden Hospital (2.5 miles south) and Hypocaust Museum (1.6 miles north-east). Open spaces near Appspond include Longspring Wood and Verulamium Lake.
What affects the cost of external mastic
We do not publish a price list, because jobs vary so much. What we look at:
- Whether there’s mould to deal with
- Whether old sealant or filler has to be cut out
- The number and length of the joints
- The type of sealant required
Combining jobs into one visit is usually more efficient than separate visits. You will get one clear quote for the whole job.
What we need to know
Photos by email are helpful but not essential. Please mention:
- Where the job is, and your postcode
- If someone has resealed it before
- Whether it’s a home or a business
- What the problem is, such as mould, gaps, leaks or cracking
We don’t publish a price list, as no two jobs are quite the same. Instead, we send you a clear quote for your job. To get started, call 0345 464 0079 or email us.
Do you need external mastic in Appspond?
Using the wrong sealant is another common reason. A high-modulus or general-purpose sealant can be too rigid for a busy joint, so it pulls away from the edges.
The most common problems we see are:
- Rain getting behind render or cladding at a joint
- Leaking joints around cladding and façade panels
- Brick movement joints where the sealant has split
- Cracked joints where brick meets render or frames
Schools such as Marlborough Science Academy are buildings too, and larger buildings have long runs of movement joint that eventually need resealing.
Questions to ask before booking
- Who turns up on the day
- What guarantee comes with the work
- Whether the sealant suits the joint
- Which colour the sealant will be
Surface by surface
Brickwork movement joints
Brick walls have vertical movement joints to absorb expansion. We reseal them with a low-modulus sealant over backing rod in a colour to suit the brick.
Render joints
Water behind render can lead to blown patches. A sound joint keeps the render dry behind and helps it last.
When something else is needed
To be straight with you, there are a few things sealant won’t fix:
- Cracking across the wall rather than at a joint
- Adding movement joints to masonry that has none
- Structural movement, which needs a surveyor or engineer
Not sure which it is? You can call 0345 464 0079 or send us an email and we’ll tell you honestly.
Surfaces we seal
- Copings & trims
- Concrete & block
- Brickwork movement joints
- Joints between brick and frames
- Façade panels
- Render & cladding joints
What we do, step by step
Once we’re on site, we check the joints match what you told us. If anything is different, we explain it before carrying on. Most jobs then take a few hours for a handful of joints, longer for a whole elevation. Somewhere as small as Appspond, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- For business premises, tell us about site rules or sign-in
- Move anything stored near the joints
- Keep pets and children clear of the area while we work
Get a quote
For a quick quote, get us on the phone, or email us if that’s easier. Tell us about the joints that need doing and we’ll explain what’s involved before giving you a price.
Read more
Towns and villages near Appspond
Also in Appspond
Should I try it myself first?
A DIY attempt does not rule out a professional job. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
Keeping the joints in good condition
Aftercare is simple:
- Check external joints each spring
- Keep soil, plants and ivy away from the joints
- Make sure movement joints aren’t pointed over
- Keep water from gutters off the wall
Give the sealant the cure time we tell you before anything rubs against it. Most exterior sealants skin fast but take longer to cure right through.
A joint that has stopped moving pushes the movement elsewhere, generally as cracking in the brickwork or render nearby. Resealing it early helps prevent that.