Unfinished Fire Doors

What makes unfinished fire doors different?

Unfinished fire doors leave the factory as bare timber, with no lacquer, oil, stain or primer applied. You may also see them sold as untreated fire doors, and either way the finishing becomes part of the job on site.

That’s extra work, but it’s exactly why many people choose them. Oak looks quite different depending on what goes on it. A clear matt lacquer keeps it close to its natural pale tone, whereas most oils deepen the colour and draw the grain out. If you’re matching a staircase, skirting or doors you already have, finishing your own is far more reliable than picking a factory shade from a photograph.

Nor is unfinished the same as primed: a primed door already carries a white base coat for paint.

Whatever you put on, finish the timber and never the fire protection. Keep every coat off the intumescent seals, and don’t paint combined intumescent and smoke seals with brush or fin strips at all. The certification label or plug should stay clean and readable too, as it’s how an inspector confirms the door is what it says it is.

It’s also worth remembering that a raw oak fire door is only one part of the system. It performs as a doorset, together with a suitable frame, intumescent seals, fire-rated hinges and a closer wherever one is required.

Unfinished fire doors at a glance

Every door carries a 10-year manufacturer’s guarantee, and the full specification is on each product page.

Unfinished oak fire doors: panelled, period and modern

Most of the oak designs among our unfinished fire doors are veneered over a solid or fire-resistant solid core, from LPD and Deanta.

LPD offers the widest choice of styles:

• Classic panelled: the four-panel Shaker and London, the three-panel Lincoln, Idaho and Kilburn, the five-panel Wexford and the seven-panel Carini.
• Period character: the DX 30s with recessed panels and the Regency RM2S with raised mouldings, a natural fit for older houses.
• Clean and modern: the Belize with its vertical grooves, the single-panel Pattern 10 and the Mexicano.
• Glazed: the Mexicano Half Light, an unfinished glazed fire door with clear glass in the top half to borrow light for a dark hallway.

Deanta’s range takes in the Walden, Norwich, Kingston, Eton, Ely, Cambridge, Galway and Coventry, with glazed versions of the Galway and Coventry. Take the Galway as an example of an unfinished oak veneer fire door: it’s faced in North American white oak and glazed with clear toughened glass.

Because veneer is a natural material, no two doors have quite the same grain. Finish the doors for one room or hallway together and they’ll mellow at the same rate. Like the look but not the work? Some of these designs also come factory-finished in our oak fire doors range.

Plywood doors for offices and shared corridors

Premdor’s plywood range is built for offices, surgeries, schools and communal corridors rather than living rooms. Each unfinished plywood fire door has a plain face over a fire-resistant solid core and is ready to be painted to suit the building.

The 2L has two clear wired glass panels down one side and the Top Square a single square vision panel near the top, both rated FD30. The 1 Long Light has one tall vision panel with a white trim and is rated FD60 at 54mm.

A vision panel lets people see who’s coming before they push the door open, which is why an unfinished office fire door like these is so often chosen for busy corridors. For other layouts, including primed and pre-finished versions, have a look at our office fire doors.

FD30 or FD60: choosing a rating for unfinished fire doors

The rating tells you how long the doorset held back fire in testing: 30 minutes for FD30 and 60 minutes for FD60. Across our unfinished fire doors, FD30 leaves are 44mm thick and FD60 leaves are 54mm.

An unfinished FD30 fire door covers most domestic work, such as the doors off a protected hallway or landing. FD60 tends to be specified on commercial projects and in larger buildings where the fire strategy calls for it. Either way, take the rating from your drawings, building control officer or fire risk assessor rather than from the design you like best.

If you need an unfinished FD60 fire door, the choice is smaller. The LPD Belize Oak FD60 gives you the same vertical-grooved design as the FD30 Belize in a heavier 54mm leaf, alongside the Premdor 1 Long Light office door and LPD hardwood blanks for bespoke work.

A 54mm leaf won’t fit a frame made for a 44mm door, so check the frame rebate before ordering and use fire-rated hinges suited to the extra weight. Every 60-minute design, finished or not, sits together on our FD60 fire doors page.

How to finish an unfinished fire door

The manufacturer’s own finishing instructions always come first, so read them before you open a tin. The basics below apply to almost all unfinished fire doors.

• Store it flat. Keep the door in its packaging, flat on level bearers in a dry room. Avoid freshly plastered rooms, which give off a surprising amount of moisture as they dry.
• Finish before you hang. Seal both faces and all four edges, including the top and bottom, plus any cut-outs for hinges, locks and handles. Unsealed edges take up moisture unevenly, which is a common reason doors bow or twist.
• Sand lightly between coats. Fine abrasive paper is all you need. Steer clear of wire wool on oak, as tiny steel fibres react with the tannin in the timber and leave black marks.
• Use the right finish. Choose an oil, lacquer or varnish made for interior hardwood on oak, or paint on plywood, and stick to the drying times on the tin.
• Mask the seals and label before the first coat goes on.

If the door needs trimming, stay within the limits in the manufacturer’s fitting instructions and seal the cut edges straight away. Some manufacturers don’t allow the top edge of a fire door to be trimmed at all.

Thinking of painting an oak door rather than oiling it? Our guide on whether you can paint fire doors explains what’s allowed and what isn’t.

Unfinished fire doors or pre-finished: which suits you?

Fire doors for finishing on site make the most sense when you need to match existing timber, want a particular shade or are fitting a batch and can finish them all in one session. Buying unfinished fire doors in quantity is also where the saving starts to add up, so if you’re kitting out a development or several rentals, set up a trade account before you order.

Pre-finished doors are the better bet if you’d like to hang a door the day it arrives, have no clean, dry space to work in, or need an identical factory finish across a whole flat or rental.

Fitting unfinished internal fire doors alongside ordinary ones? Our unfinished internal doors carry the same bare oak look into the rooms that don’t need fire protection.

Unfinished fire doors: your questions answered (FAQ)

Why buy an unfinished fire door?

Mostly for control over the final colour. You choose the finish, so matching existing oak joinery is much easier. Unfinished fire doors also tend to cost a little less than the same design pre-finished, which adds up across a whole house or development.

What must I finish, and what must I leave alone?

Seal both faces, all four edges and every cut-out, and leave the seals and certification label uncoated.

Does finishing affect the fire certification?

Finishing the timber as the manufacturer describes is simply how these doors are meant to be completed. Problems start when finish ends up on the seals, which have to expand freely in heat, or covers the label that identifies the door.

Which unfinished fire doors are FD60?

The LPD Belize Oak FD60, the Premdor Plywood 1 Long Light office door and the LPD hardwood door blanks, all 54mm thick. Everything else in this category is FD30 at 44mm.

What sizes do unfinished fire doors come in?

Most come in the common 78-inch (1981mm) imperial height in standard widths, and some office designs go wider. Exact sizes are listed on each product. Measure the frame opening rather than the old door, and check the frame is deep enough for a 44mm or 54mm leaf.

Are unfinished fire doors cheaper than pre-finished ones?

Usually, yes, because the factory finishing step is left out. The LPD Mexicano Half Light comes in both versions, so you can compare the two on their product pages. Once you add the cost of the finish and your time, the saving matters most on larger jobs.