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Technical Details

Technical Help & Advice

Leader Doors are the experts when it comes to doors. We are able to advise on anything from fitting to finishing and are always on hand Monday to Saturday for any questions you may have, however big or small!

Please take a look at the page below, where we will aim to answer some of the more frequently asked questions.

If your questions are not answered on this page, or you simply wish to speak with one of our Dedicated Technical Advisors, you can contact us on 01429 241 270 or email us at

Door Size Guide

When purchasing new doors you will more than likely find that your property does not have one standard size throughout the entire building. This doesn't mean you should worry, as this is the case for almost all properties. That is why we offer a huge range of sizes on most doors, to ensure that you can choose a door to suit your entire home!

Take a look at our handy Door Size Guide, which you can use as a guideline when choosing the doors that you need.

Please Click Here to view the door size guide.

Engineered & Solid Construction

Most of the doors we supply are built with an engineered construction. This means that the door is built with a core of manufactured timber, such as laminated timber, MDF or particleboard. A real wood veneer is then applied to all faces of the core, giving you the final solid timber appearance and feel.

Engineered doors are the preferred choice for most installations, as they offer increased stability. These doors will not bow, twist or warp when subjected to general humidity and temperature changes throughout the year, ensuring they are the most secure option when choosing new doors for your home. As our doors are manufactured from natural timber products, grain variations and colour differences can be expected throughout the range. Also worth noting, engineered cores can vary in weight from time to time, depending on the density of the particle board used within the core of the door. This should not cause alarm, but should be noted as doors may feel lighter than expected. Our doors come with two particleboard densities, 650kg/m³ and 725kg/m³.

Solid construction doors are manufactured using one solid piece of real timber. These doors are perfectly suitable for use inside the home once properly finished, but are not recommended for use in external situations.

Adjusting Your Door

Door opening sizes can differ from location to location and can also differ depending on the age of the building in question. This means that not all doors will fit into every opening. This is why Leader Doors offer a huge variety of door size options with every style of door, as we aim to ensure that our doors will fit anywhere in your home.

If the closest size door is too small for your frame opening, then you may need to pack out the frame with additional pieces of timber. This will effectively reduce the size of your frame opening and will ensure there are no gaps when it comes to fitting your door.

Alternatively, if the closest sized door available is too big for your frame opening, you will need to trim down the size of the door until it fits. This is a job that any competent joiner (or even yourself if you have the knowhow) can do fairly easily.

Of course, when it comes to trimming a door down in size there are some recommended guidelines for how much you can take off before damaging the stability of the door. These guidelines are outlined below;

Engineered Timber Doors

Deanta: All Deanta doors are specially manufactured with extra thick 18mm solid wood veneers. These doors are fantastic for those customers looking to take off a larger amount, as they allow up to 16mm from each side. This means that you can safely reduce the door by a maximum of 32mm (16mm from each side) on all four sides of the door.

Other Brands: All of our other standard timber doors are manufactured with 10mm solid wood veneers. These doors allow up to a maximum of 8mm from each side. This means you can safely reduce the door by a maximum of 16mm (8mm from each side) on all four sides of the door.

White Moulded & White Primed Doors

Leader Doors advise that no more than 6mm be trimmed from each side of any solid white primed or white moulded door. Due to the construction of these engineered doors, if can often mean that they become unstable when reduced by any more than 6mm.

Fire Doors

We recommend that under no circumstances should a fire door be altered in size, as this could affect the fire rating of the door and may mean it does not stand up to fire safety regulations. If you require a fire door in a custom size, then please contact us and we will enquire with our suppliers to see if one can be made to suit your needs.

If you are unsure, please contact us before performing any work on your doors and we will be happy to help. We are unable to replace or refund any doors which have been worked upon as they are deemed to be accepted.

Finishing Your Doors

Leader Doors can provide a highly professional and quality factory spray finish on any of our un-finished timber doors. Our quality spray finishing service provides a superb finish to any internal door, ensuring a smooth, clean finish on all sides with no sanding, painting or brush marks.

When finishing your door at home, it can be extremely difficult to ensure that your door is as smooth as a factory finish, especially on all sides. Our finishing service is a fantastic way to ensure you get the finish you desire, without the hassle or mess that home finishing can bring.

If you would like us to Fully Finish your door(s), then please add the finishing service Here to your basket alongside your order.

If you would prefer to finish your doors at home, we can recommend a number of high quality door finishing products, which will perfectly complement our doors, simply contact us and we'll be able to help.

Glazing in Our Doors

All glass in our doors is toughened safety glass, manufactured to fully comply with BS6206. This ensures that all of our glazed doors are fully compliant with UK building regulations. All of our glazed doors carry the EU regulation Kitemark for toughened safety glass.

Each type of glazing differs in thickness, which is outlined below;

Flat Glass: 4mm approx.
Bevelled Glass: 6mm approx.
Double Glazed: 14mm approx.
Triple Glazed: 18mm approx.

Door Care Information

- Upon unpacking, every door must be thoroughly checked for faults/damage and any faults/damage must be reported to us within 24 hours of receipt of your order.
- All doors must be treated, prior to installation on all sides of the door, to protect the door against moisture and the elements.
- Upon receipt, every door must be hung. If installation is not possible all doors must be stored flat in dry conditions until required.
- All doors must be covered to keep them clean and they must be kept out of direct sunlight.
- Doors should be handled with clean hands, or clean gloves, and must not be dragged across one another or other surfaces.
- Doors should not be stored in a room that has been recently plastered or where they may come in to contact with excess moisture i.e. steam, as this will cause damage to the timber.
- Doors should not be subject to abnormal heat, extreme dryness, humid condition and/or sudden changes in terrain.
- Doors should be acclimatised to average conditions of the installation location prior to installation. They should be stored in the room where the door will be installed prior to hanging in order to ensure they become conditioned to the present moisture levels.
- Doors should be trimmed equally on both sides. No more than the recommended should be trimmed from the doors (outlined in 'Adjusting Your Door Size').
- Before applying the final finish to the doors, remove handling marks and/or effects of moisture exposure with a thorough final sanding over all surfaces of the doors using fine sandpaper.
- Do not use steel wool and/or other sanding materials containing steel/iron on any doors, especially Oak doors.
- Clean doors before applying a sealer and/or finish. Some species of wood, especially Oak, will cause a natural chemical reaction that can adversely effect certain finishes.
- Where possible, the surface of the doors should be tested for adverse reactions to finishes. The application of a sealer before finishing will usually prevent this.
- Before hanging doors ensure all faces, all four edges and areas which have been rebated for handles, hinges and/or locks are fully treated with paint and/or preservative.
- Before hanging any doors, all all faces and edges should be treated with a suitable paint or sealer.
- Adequate drying time must be allowed between coats, please refer to instructions from the manufacturer of the specific finish for drying times.
- Exterior grade finishes should be used on all faces and sides for exterior doors.
- Avoid dark colours on exterior doors in direct sunlight.
- Doors should not be exposed to adverse conditions until it has been properly finished by the application of suitable treatments.
- Regular maintenance is highly recommended to prevent the breakdown of finishing coats and to further protect the timber from deterioration.
- Leader Online Ltd, trading as Leader Doors, shall not be held responsible for any incidental work or problems resulting from poor workmanship applied to the doors.