Door installation and painting

Professional installation ensures the door hangs perfectly, operates smoothly, and provides a tight seal against the elements. A high-quality paint or stain finish then protects the timber from moisture and wear, ensuring your investment lasts for decades rather than years.

What Does the Work Involve?

• Survey and Measurement: Precision measuring of the existing opening to ensure the new door and frame will fit perfectly without excessive trimming.
• Removal and Disposal: Taking down the old door and frame, ensuring minimal damage to surrounding plasterwork, and disposing of waste responsibly.
• Preparation: Trimming the new door to size (if timber) and mortising hinges, locks, and handles into the wood.
• Installation: Fixing the frame, hanging the door, and installing weather seals and thresholds for external units.
• Surface Prep: Filling nail holes, sanding the timber to a smooth finish, and knotting any resinous areas in the wood.
• Painting/Staining: Applying a primer or base coat followed by at least two topcoats, including the top and bottom edges to prevent moisture ingress.
• Ironmongery: Fitting the final handles, letterboxes, and locks once the paint is fully cured.

Typical Costs

Prices vary significantly between simple internal hollow-core doors and high-security external composite or solid oak doors. These estimates include VAT and reflect 2025/26 UK market rates.

The primary cost drivers are material quality (MDF vs Solid Oak), the complexity of the ironmongery, and whether the frame needs replacing. For external doors, thermal efficiency ratings (U-values) also influence the price point.

How Long Does It Take?

• Single Internal Door: 2–4 hours for hanging; painting adds 1 day (including drying time).
• Front Door & Frame Replacement: 4–8 hours for a standard installation.
• Multiple Internal Doors (Whole House): 2–3 days depending on the number of doors and complexity of the trim.
• Painting/Finishing: Usually requires 24–48 hours total elapsed time to allow for proper curing between coats.

DIY or Professional?

While hanging a single internal door is a common DIY task for those with good carpentry skills, external doors are a different matter. Professional installation is highly recommended for external doors to ensure compliance with Building Regulations (Part L) regarding thermal insulation and security.

Professional joiners have the specialist tools, such as routers and sharp chisels, required to create the clean recesses needed for a "factory finish" that DIYers often struggle to replicate.

If you are installing a fire door, it must be fitted by a competent person to ensure it meets life-safety standards. Incorrectly fitted fire seals or hinges can render the door useless in an emergency.

Choosing the Right Tradesperson

• Check Qualifications: Look for NVQ Level 2 or 3 in Bench Joinery or Site Carpentry.
• Accreditations: For external doors, look for FENSA or CERTASS registered installers who can self-certify their work.
• Reviews: Look for specific mentions of "attention to detail" and "cleanliness," as painting and sanding can be messy.

Questions to ask:

• Will you paint the top and bottom edges of the door to prevent warping?
• Are the hinges and locks included in your quote, or do I need to supply them?
• How do you protect my carpets and furniture from sawdust and paint fumes?
• Do you provide a FENSA certificate (for external doors)?

UK Regulations

• Part L (Conservation of Fuel and Power): Replacement external doors must meet minimum U-value requirements for thermal efficiency.
• Part M (Access): Some renovations may require a minimum clear opening width to allow for wheelchair access.
• Part B (Fire Safety): Internal doors leading to garages or in certain hallways (especially in flats) must be fire-rated (usually FD30).
• FENSA/CERTASS: If replacing a door with more than 50% glass, the installer should ideally be registered with a competent person scheme.

Common Problems

• Binding or Dropping: If hinges aren't recessed correctly or the frame isn't square, the door will rub against the floor or jamb.
• Paint Peeling: Often caused by failing to use a primer or painting over "knots" in the wood without a knotting compound.
• Poor Security: Using "contract grade" locks on an external door makes it vulnerable to bumping or snapping.
• Warping: This happens when the installer fails to seal the top and bottom edges, allowing moisture to enter the grain.

Frequently Asked Questions

Can I paint over a pre-finished door?

Yes, but it requires specific preparation. You must lightly sand the factory finish to create a "key" for the new paint and use a high-adhesion primer like Zinsser BIN before applying your topcoats.

Why is my door sticking in the winter?

Timber is a natural material that expands when humidity is high. If the door wasn't sealed properly on all six sides, it absorbs moisture and swells. A professional can plane the edges and reseal it to fix this.

Do I need to replace the frame as well as the door?

Not always. If the existing frame is square, rot-free, and sturdy, you can simply "hang" a new door. However, for external doors, buying a "pre-hung" set (door and frame together) usually provides better security and weatherproofing.

What is a "fire door" and do I need one?

A fire door (usually FD30) is designed to resist fire for at least 30 minutes. You typically need them in doors leading to an integral garage, in loft conversions, or in flats that open onto a communal hallway.

How many coats of paint are needed?

For a professional finish on bare wood, you should apply one coat of primer/undercoat and two topcoats of eggshell, satin, or gloss. Always sand lightly between coats for the smoothest result.