Door Threshold Sealant and Door Frame Sealing for Patio and Entrance Doors
A gap at the foot of a door or round its frame lets in water, draughts and insects. Our team applies door threshold sealant and door frame sealant to front doors, back doors, patio doors and bifolds, cutting out the old mastic and sealing the joint properly.
Why door joints let the weather in
A door is one of the most exposed openings in a house. Rain is driven against the threshold, the frame is heated by the sun in the afternoon and chilled by frost at night, and the door is opened and closed hundreds of times a year. The mastic between the frame and the wall slowly cracks and shrinks, and the seal under the threshold wears out.
The result is often a cold draught round the door, a damp patch on the floor inside or a dark stain on the plaster beside the frame. Fixing the sealant is usually far simpler than replacing the door, and it is a job we do every week. Whether it is front door sealant, back door sealant, bifold door sealant or door frame mastic on a composite door or uPVC door, we use the right sealant for door frames made of any material.
Door joints we reseal
Threshold to sill
The joint between a threshold and the step or sill, where rainwater often gets in.
Frame to wall
The external joint round the frame, replaced with fresh flexible sealant.
Patio doors
Patio door sealant at the frame, the track and the sill, for sliding and French doors.
Bifold doors
Joints round bifold and sliding systems where the frame meets brick, render or cladding.
Composite and uPVC doors
Door frame sealant in white, grey, black, anthracite or woodgrain shades.
Internal reveals
The inside joint between frame and plaster, neatly sealed so the reveal looks right.
We seal the joints. We do not replace door seals, thresholds or frames themselves, and if a door needs adjusting or a threshold is damaged we will say so.
How we reseal a door frame and threshold
Cut out
All old sealant is cut away from the frame, wall and threshold edges.
Clean and dry
Dirt, algae and loose material are cleaned off and the joint is dried.
Back and prime
Backing is fitted in deeper gaps, and primer is used on porous masonry where needed.
Seal and tool
New sealant is applied and tooled so water runs away from the door.
Where the threshold sits on a step, we shape the bead so water drains off it rather than collecting along the edge.
Sealant choice and colour
External door joints need a flexible, weather-resistant sealant. We use and apply Arbo, Sika, Dow, Soudal and Everbuild products, selecting silicone, modified polymer or polyurethane to suit the frame and wall materials. Colour is matched to the frame from our sealant colour charts, so the finished joint is tidy rather than obvious.
- Flexible sealant that copes with sun, frost and door movement
- Colour-matched to uPVC, aluminium, timber and composite frames
- Neat, straight lines, with no sealant smeared on the glass or the frame
- Advice on how long to leave the joint before it gets wet
Houses, flats and commercial entrances
Homeowners use us when draughts or damp appear round the front or back door. Landlords and property managers book us to reseal entrances across blocks. We also seal door frames on shops, offices and schools. For the rest of the house see window and door mastic and window sill sealant.
Our team has over 20 years in construction behind it, and we cover London, the South East, the Midlands, the East of England and the South.
Insured & pre-qualified
Peace of mind for homeowners, builders and main contractors.
- £10m Employer’s LiabilityInsurance cover
- £5m Public Liability & Professional IndemnityInsurance cover
- Constructionline Silver member
- CSCS Skilled WorkerSealant Applicator (NVQ Level 2)
Over 20 years in construction
Products we use
Professional-grade sealants and adhesives from leading manufacturers.
Brand names and logos are trademarks of their respective owners and are shown to identify products we use. No endorsement is implied.
Door frame and threshold sealing: common questions
Why is water coming in under my door?
Often the sealant between the threshold and the sill or step has failed, or the frame joint has cracked. A fresh, well-prepared bead usually fixes it, but we will tell you if the threshold itself is damaged.
Can you seal round patio doors and bifolds?
Yes. We seal the frame, track and sill on sliding patio doors, French doors and bifold doors.
Do you replace the rubber door seals?
No. We apply sealant to the joints round the frame and threshold. Worn rubber seals and damaged thresholds are a job for a door specialist.
Can the sealant colour match my door frame?
Yes. We match white, grey, black, anthracite, woodgrain and other frame colours from our colour charts.
Draughts or damp round a door?
Send a photo of the threshold and frame and we will let you know what is needed. Send a photo on WhatsApp, email office@pioneersealants.co.uk or call 01234 607 252, and we will tell you what is needed.
- Opening hours
- Monday – Friday8:00am – 6:30pm
- Saturday9:00am – 4:00pm
- SundayClosed
