How to measure up and prepare for fitting a loft ladder or folding attic stairs.
There are only 3 important measurements you need to know before you order a Stira* or any loft ladder.
1. Ceiling height
This is the most important measurement, in many cases it is the only measurement you need to buy a loft ladder. Measure the vertical distance from the floor to the ceiling (not floor to floor). Double check this measurement to ensure it’s correct.*
*Customers in Ireland and the UK do not need to know any of these measurements to purchase a Stira. Stira customers can request a free consultation by one of our fitters/distributors. However providing a ceiling height before calling can speed up the ordering process.
2. Rough opening width
The frame width is the outer dimensions of the loft ladder frame, the frame of the loft ladder is fixed to the joists in the ceiling so it is important to ensure the frame will fit in between the joists.
To ensure you select the correct loft ladder that will fit between the joists in your attic measure the rough opening between the joists in your ceiling, this will give you the rough opening measurement. This measurement will often be slightly larger than the width of the loft ladder but that’s ok and intentional, it is preferable to have a gap to allow for squaring the frame during fitting. Double check you are measuring between the ceiling joists, the hatch can quite often include additional framing that will be removed or replaced when fitting the loft ladder or folding attic stairs.
3. Rough opening length
There is no need to match a loft ladder frame length to the opening length of your current hatch as extending this dimension to match the frame length of the new loft ladder is a common step in fitting a loft ladder. Extending the opening length can be done quite easily as the installer is cutting a joist that has already been cut so no new joist is cut in the process.
Note: One thing you do have to do however is make sure you have the room to extend, check in the direction you intend to extend the opening to ensure there are no wires, water pipes, walls or joists/beams in the way. Make sure that you will have adequate head room to step up off the loft ladder into the attic after installation and that there is adequate floor space to walk into the attic from the top of the loft ladder after installation. Try to install the loft ladder so that it is pointing into the centre of the attic space as this will help ensure you have the most headspace when walking up the ladder.
If you are replacing one brand of loft ladder with a different brand it is important to take note of the difference in the opening lengths. For example a one size fits all loft ladder can have a very long frame length to accommodate many different ceiling heights, while a loft ladder made for a specific ceiling height can have a shorter frame length to preserve floor space in the attic. If the new loft ladder is shorter than the old one meaning there would be a gap along the length of the opening there are three options. The first option is to put in new plasterboard, replaster and paint the gap however this could turn into a big job trying to match the old paint. If the gap is not that large the second option would be to cover the gap with larger architrave, this option is easy and straightforward to achieve. The third option is to custom build the new loft ladder to match the frame length of the old loft ladder. This option would be more a more convenient and cheaper option than replastering larger gaps.
Extending the hatch opening length is all part of the Stira fitting service. All Stira fitters (Ireland) and distributors in the UK can quickly and expertly extend the opening and give advice on the best way to extend the opening. If the current hatch is unsuitable a new opening can be made in a more suitable place.
What about clearance above the opening?
With 3 part folding loft ladders space above or around the opening is rarely an issue as these type of loft ladders fold onto themselves meaning they do not extend beyond the frame of the loft ladder. The total height of the loft ladder is generally less than 18” (45cm) and that measurement starts from the ceiling below not the floor of the attic. The major concern with clearance above the opening is for peoples heads and not the loft ladder itself. Ensure there will be enough room to comfortably stand up when stepping off the loft ladder.
Sliding ladders and two part ladders require more space and planning. Sliding ladders require floor space in the attic, this space can be as long as the ceiling height so this would need to be considered before installation as that floor space cannot be used. Many two part ladders do not extend beyond the frame of the loft ladder however some require height above the opening as the ladder does not fold flat on the trapdoor. This height can be roughly 1 metre above the opening.