How to construct door openings to different duty ratings
Construct door openings that meet Light and Medium Duty or Heavy and Severe Duty Ratings to satisfy BS 5234: 1992.
This video explains the difference between constructing Light and Medium Duty and Heavy and Severe Duty door opening ratings to meet BS 5234: 1992.
H2: Light and Medium Duty door openings
For Light and Medium Duty Ratings, the floor channel on the metal stud partitions is stopped at the door opening, with the studs either side being fixed into position with a British Gypsum Wafer Head Drywall Screw or a crimping tool.
Form the head of the opening with the channel returning down the face of the stud by 150mm. Fix in place with wafer head screws or a crimping tool, twice to each side of the stud at each side of the opening.
Timber sections are then placed within the stud each side of the door opening. This will also provide a fixing for the door frame. That’s the Light to Medium Duty Rating now complete; advice should also be sought from the door manufacturer.
H2: Heavy and Severe Duty door openings
Now we’ll look at the Heavy and Severe Duty door opening. This time, when we’re fixing the floor channels in place, we allow the channel to be 300mm longer at the door opening. This is then snipped and bent up into position for the correct width of the door opening. Four fixings are used within 150mm at the opening of the channel; this is an important step towards achieving the Heavy and Severe Duty Rating.
Once the door opening is formed, continue to cut lengths of channel to fit between the returned channel at the floor and the head. This is then cloaked over the metal stud at the doorway. Once the channel is cloaked over the stud, this will then allow direct fixing of door frames through the stud and channel at the door opening.
It’s important to note that door frames should be pre-drilled and countersunk before fixing into position with the appropriate length screws. Door casings can be fixed in place before or after plasterboard is fixed in place.
That’s the Heavy to Severe Duty Rating now complete. Seek advice and guidance from the door manufacturer, particularly for doors that weigh over 60kg.
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