National Hickman

Our team of sales engineers (who can be contacted every day during UK business hours), will be pleased to answer your enquiry. However, you may find the following FAQs valuable.

Questions about…

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Doorkits

What size should I make the structural openings?

As a general rule, all structural openings should be made 60mm wider than the door widths and 50mm higher than the door height. for pairs, add a further 3mm. I.e. for an 838 x 1981mm door the opening should be 898 x 2031mm. This will allow for packing out, around the frame.

Can we fit the Linings at the First fix stage, pre-plaster?

We strongly recommend that all the frames are fitted after the plaster has dried, (as wet plaster skim can cause swelling and distortion). The use of Plywood Sub-linings in Block wall openings is recommended.

Why do you NOT recommend storing Doorkits products in containers?

Warm air holds a greater amount of moisture than ‘cool’ air. In a confined space, with little or no ventilation, the capacity of air to hold moisture is limited. If a container full of warm air cools (typically at night) the air can quickly no longer hold the moisture, and condensation forms. These are KILLER conditions for wood based products.

Can we hang the doors at Second Fix?

This is NOT recommended as in damp conditions, doors can swell and distort. Doorkit doors are fully finished*, and should always be hung at final fix, when the dwelling has dried out sufficiently.

Should we turn the heating up to help dry the houses out, before hanging the doors?

When central heating is turned on, it should be set to run day and night at a constant temperature, (Max 15°C) to avoid warm conditions in daytime followed by cold at night. Keep plots well ventilated: open all window vents, set upstairs window sashes on ‘night vents’ position. -See "Getting the best from National Hickman Internal Doorkits on UK Building sites"

Do we need to lubricate hinges and what should we use?

Lubricate where required with suitable light machine oil. Apply with care to the hinge knuckle joints. Open & close the door several times to aid lubrication. Wipe away any excess oil with a soft cloth. Find out more about Care & Maintenance.

I Joists

Can we cut or notch the flanges of I joists?

No. Under no circumstances must the flanges of joists be cut or notched. Should a flange become damaged, please complete the Remedials form and return to the National Hickman design centre for remedial action to be advised.

Can we cut service holes in the web of I joists

Yes, please follow the circular and rectangular hole installation guides as printed in the JJI-Joist Technical Manual (fourth edition). Please also refer to JJI Technical bulletin 7 revision A.

Can we connect an I joist to a steel beam?

Yes. Please see Technical bulletin 25 (Revision A).JJI-Joist entitled 'JJI-joist to steel beam connection'.

What fire protection do I joists offer?

They offer a variety of methods of achieving both 30 minute and 60 minute fire protection. Fire tests were carried out by Chiltern International Fire.

Can I use I Joists in a ground floor construction?

Yes, however, various factors must be taken into account. For more information on the design of ground floors using I-Joists, consult JJI-Joist Technical Bulletin 9 (Revision B) Ground floor design and restraints.

Can I Joists be used in the construction of roofs?

Yes, they can be used in the design of both flat and pitched roofs. JoistMaster V3 allows the user to design flat and pitched roofs.

Fibercill

Can you produce 'special' profiles to specific dimensions?

Yes – National Hickman are able to offer a fully bespoke, special profile machining service enabling us to match new and existing profile requirements to exacting specifications. Prices, lead times and individually tailored CAD drawings are available on request.

Are all mouldings primed?

Yes – all National Hickman MDF moulding products come sanded, de-nibbed and twice primed using a factory applied water based primer.

What is the correct way of storing MDF mouldings on site?

All Fibercill MDF mouldings should be stored flat (not upright) and under cover, and never submitted to excessive wetting. Packs should be placed on even bearers to prevent distortion and never stored in un-ventilated containers.

What are the best methods for fixing MDF mouldings?

Fibercill MDF mouldings are easily worked using conventional woodworking tools and can be fixed using a proprietary high performance contact adhesive and lost head or helical nails. Find out more about fixing instructions.

Are all the MDF mouldings that you supply, moisture resistant?

Yes - All Fibercill MDF mouldings that National Hickman supply are moisture resistant. The green dye has been removed for aesthetic reasons,(to give it a whiter appearance when primed.)

Are all Fibercill mouldings supplied by National Hickman FSC certified?

Yes – they all meet the requirements for the FSC chain of custody standard, and contain a minimum of 70% FSC certified virgin fibres.