IS YOUR LOFT CEILING STRONG ENOUGH FOR LOFT STORAGE?
I get asked a lot about how strong a ceiling needs to be, or will it be able to take the weight of boarding on the existing ceiling.
A ceiling is a ceiling that is all it is meant to be. They were built to hold up the plaster board or lathe plastered ceiling and for the occasional walking on the joists for services reasons.
Some older properties, because of the type of roof timbers such as a purling support system or a trussed roof, will make a difference to the overall strength.
Older ceilings like a Victorian terraced, tend to have a purling supported roof, which is a big beam from one supporting wall right through to the supporting wall opposite. Some have extra support in the centre, which rests on the internal supporting brick walls so the purlings do not sag over the years.
If you have ever had a look inside an older terraced house style loft, you may have seen strips of wood hanging around attached from ceiling to roof? These are known as hangers, and they are there to give extra support (especially in the centre of a bedroom) to prevent the ceiling joists from sagging over the years.
Usually 3x2 timber joists run from the back wall under the eaves of the roof to a central wall for support, then from the central wall another set of joists run to the front of the house under the eaves. A lot of older properties suffer from ceiling sag which is normal because the roof may have also sagged but the hangers come loose where the nails have rusted away so they stop bearing weight. These all need to be checked and broken or loose ones need to be replaced with modern timber versions anyway before considering boarding.
So will your ceiling take the weight required to board, store and to walk upon?
The answer is yes, if done correctly.
Adding a batten (2x1 or 2x2) strip of wood is nowhere near any use or support and hardly adds any strength to the existing ceiling. New supporting timbers must be much more substantial than this.
Also you can't get hardly any insulation underneath to insulate your home.
It’s not rocket science, but some “cowboy builders & joiners” really have no clue. But a specialist will know all there is to know about doing this job correctly.
Here are a few ways to add strength and support for a professionally built loft storage area:
• Check all ceiling hangers are fixed and not rotten or broken, replace if they are.
• Check ceiling joist thickness must be at least 3 inches by 1.5” (75mm x 38-40mm)
Any thinner than this and a suspended floor will have to be installed
• Construct a new floor frame called a sub-frame out of minimum 4”x2” set at 24” centres
• Lay the frame in the centre of your loft with the supporting wall in the middle of your
frame and the outer edges underneath a purlings
• The reason for this is the central area weight will be taken on the supporting central
wall of your Victorian house, which goes all the way through to the ground floor footings
and the overhang under the purlings is so you can add purling hangers to your sub-frame
• Adding purling hangers to the sub-frame will take the weight and allow you to level the
floor in line with where the sub-frame fits on the central supporting wall (highest point)
• Hanging the frame on the purlings will take off any pressure to the ceiling joists below
and will raise it enough to get insulation underneath, as well as allowing important air
flow ventilation through the insulation.
• Once the sub-frame has been levelled and adequate supporting hangers have been fitted the
new sub-frame will be very strong and allow at least a couple of people and lots of storage
to be supported without any worries of it damaging your ceiling.
• Once the sub-frame has been levelled set in place and fixed down, then you can lay down the
boards, ideally in staggered formation if possible without creating waste.
• Never nail down, only screw down. You may need to remove the board at some point, and
nailing can crack ceiling plaster work with the impact.
So, if you didn’t do all this preparation work before hand and you simply laid boards on to the existing ceiling without the extra support and strengthening, don't you think you'll be asking for trouble? It will put pressure on the ceiling causing increased sag, and the more weight the worse it will become and eventually it will crack or damage the ceiling beyond a simple repair. And replacing ceiling timbers and plasterboard is very messy and very expensive to do.
Worst case scenario is that the ceiling falls through!!!
Loft boarding is part of general building, and as simple as it may sound, as a professional company we have to work to building rules and regulations. Building in general is all about making it safe to use and sticking to rules to prevent any weakening of the existing structure. Anyone choosing to ignore these rules should not be in the building profession.
SO WHAT ABOUT A NEW PROPERTY WITH A NEW TRUSSED ROOF?
A trussed roof has a lot of extra support via the web timber frame work (the criss cross timber frames in your roof)
Usually the ceiling joists are part of the actual trussed roof frame, so they are already very strong and never really require any added support if the new storage floor system being added is designed to distribute the weight evenly.
We use LoftZone StoreFloor which is a unique stilt and beam system, designed to be installed directly to the existing ceiling joists to raise the ceiling floor above the insulation, so as not to squash or remove any existing insulation, which is normally up to 270mm high.
The new metal cross beam (sub-frame) runs opposite to the existing joists, so this allows the new storage floor to distribute the storage weight more evenly and solves the problem of tall insulation getting in the way. Three jobs in one:
1. Adds better storage weight distribution
2. Raises the storage level above the insulation
3. Creates extra storage where you couldn't normally have it
Most new loft joist are around 4” to 5” tall allowing room for the first 100mm of insulation to go perfectly in between the joists, then a second 200mm layer laid opposite the first.
Being on average 2” thicker and slightly wider than it's predecessor in the Victorian era, this instantly gives the ceiling joists more support to handle modern style loft boarding solutions like the LoftZone StoreFloor system.
Normally, as we did with the Victorian house, we only use the central area. In this case, this would be the highest parts down the centre of the loft known as the apex of the roof. Using the eaves can be done, but this restricts access and the pitch of the roof is lower, which also cuts down on the storage height, so you must consider if it is worth using these areas.
So how much weight can a new loft take?
It can handle a fair bit of weight. But as a rule, if you can't lift it to the loft then that one item is too heavy, so you need to split it up in to different boxes.
Total weight is really determined by the strength of the ceiling timbers, extra reinforcement and how well the storage floor is built. Most strengthened ceilings can manage at least two or three people and many storage boxes containing general items, so long as you distribute things evenly throughout the loft then you would be surprised at how much weight can be stored in your loft.
For advice on this please ask the surveyor when they do a site survey. They will give you their professional opinion on your type of loft, as to how much storage weight is possible.
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