What size joists do I need for a loft?

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The rule of thumb for joist measurement is half the span plus 2″ measured in feet. Therefore a 10 foot span would require a 7×2 joist, a 12 foot span an 8×2 joist etc. The 3.5m span is approx 11′ 6″ therefore would require an 8×2 joist to be on the safe side.

How do I strengthen my loft joists for storage?

How to Reinforce an Attic Floor with Sister Joists

Clear the Joist Spaces. Pull out all insulation and any debris from all of the joist spaces so you can see the full length of each joist, including where it meets the exterior walls.
Measure the Old Joists.
Cut the Sister Joists.
Install the Sister Joists.
Install Blocking.

Do I need to strengthen loft joists?

Within a loft conversion, strengthening the loft floor joists is important, as lofts were not constructed to hold much more than items in storage.

Can you lay loft boards directly onto joists?

You can still board directly on to the joists if you want, but it is worth noting that this would not pass a building control inspection, because you wouldn’t have the full 270mm depth of insulation required by regulations. Whatever you do, make sure you put as much insulation beneath the boards as possible.

How thick should joists be for loft conversion?

Good rule of thumb for a floor is half the span 2.8m coverts to just over 9 feet, half of 9 is four and a half, make that inches and add 2″. So six and a half x 2″ joists is likely what you need.

How big do floor joists need to be for a loft conversion?

These new joists will run alongside the existing ones and span from one load bearing wall to another. The additional joists will usually be required to be anywhere from 200mm to 225mm in depth and will rise above the ceiling joists in order to form that new floor structure.

Can you do a loft conversion without steel beams?

Steel beams are the most popular choice for most loft conversions, however, they’re not the only option. Due to regulations, build size, style and budget, some choose to complete their loft conversion using an alternative material.

Do you need to reinforce floor for loft conversion?

You will most certainly need to strengthen loft conversion floor joists. Add in stronger and larger timber floor joists between the existing joists of the ceiling. Support them on the current walls if they are strong enough or add in extra timber if needed.

What flooring is best for loft conversion?

Solid wood flooring is usually the customer’s first choice when it comes to loft conversions. Installing traditional solid wood boards is pretty tricky, and often downright impossible in lofts. Solid wood boards are usually 20mm thick and are installed over a plank battening system laid over a subfloor.

Do you need a gap between insulation and loft boards?

Gap between insulation and loft boards

If using rigid insulation boards to insulate your loft there must be a gap between the roof covering and the insulation to allow air to circulate. This prevents any build-up of warm air that could lead to condensation.

Is it OK to board over loft insulation?

Placing loft boarding over insulation is an easy process and is essential if you want both storage and for your quilt insulation to work at its optimum performance. With the correct products, such as Loft Legs, this is easy and cost effective too.

Do you need new joists for loft conversion?

Loft Conversion Building Regulations
Floor / Beams – It’s more than likely when converting your loft you will require new floor joists to support the weight of your new conversion.

Can you use oak beams instead of RSJ?

The first being hollowed out air dried oak beams, these are a great and easy way to cover up any RSJ’S albeit steel or concrete, you don’t even need to have an RSJ to cover, you can simply use these to clad a brick wall to add instant character to your room, giving the impression that it is in fact an oak beam.

Can I use timber instead of RSJ?

You can use timber , min 200x50x2 but you will have to make it a flitch beam . This means a 10mm piece of steel in between the two timbers bolted through each other. Steel must be same size as timbers .

Should you carpet a loft?

Carpet flooring is also an ideal option for your loft room because of its sound and heat insulation properties. Your budget shouldn’t be a big deal too because you’ll find an affordable choice regardless.

What wood do you use for a floor in loft?

We’d recommend using purpose-built loft boards as they tend to have tongue and groove fittings for easy installation, and they are also often shorter, so easier to get through your loft hatch.

Can you put too much loft insulation down?

As long as you ventilate your property properly, you can have as much insulation as you like within reason. The trick with loft insulation is to balance the amount of insulation you have with the amount of ventilation necessary to prevent damp. As long as you get that balance right, you should be fine.

Can you lay loft insulation over joists?

If access is easy and your loft joists are regular, you can use rolls of mineral wool insulation. The first layer is laid between the joists – the horizontal beams that make up the floor of the loft – then another layer is laid at right angles to cover the joists and make the insulation up to the required depth.

Can loft boarding cause damp?

How Standard Loft Boarding Can Damage Your Property. Can cause damp – as standard boarding is placed onto the joists of your roof, this will inevitably squash your insulation, which stops it from working and will cause condensation to build up as it doesn’t have room to breathe.

Should I remove old loft insulation?

In most circumstances removing your old insulation isn’t necessary and it can actually be quite beneficial to leave it. This is as most insulation will retain its thermal properties so leaving it in place will mean that you continue to benefit from it whilst also having an additional layer of insulation on top!

Do loft conversions need steel?

When converting your attic, the loft space won’t have the support of internal load-bearing walls to hold the new structure. This is where steel beams are used to help bear the extra weight of your newly converted roof space. All loft rooms will require some sort of loft conversion steel beams.

Is Oak as strong as steel?

Oak has superior strength to weight ratio
In stress tests it becomes obvious that steel is over 3 times stronger than green oak, but what also needs to be remembered is that steel is 10 times heavier, and as such the strength / weight ratio of clear dry oak is superior to steel (Ross et.

Can I use an oak beam instead of an RSJ?

Can you use old carpet as loft insulation?

Perhaps that’s not as mad as it sounds: waste textiles – old clothes, curtains, carpets – are the latest materials to be developed into insulation to help save energy and lower utility bills.

What is the best flooring for a loft conversion?

Solid wood flooring
Solid wood flooring is usually the customer’s first choice when it comes to loft conversions. Installing traditional solid wood boards is pretty tricky, and often downright impossible in lofts. Solid wood boards are usually 20mm thick and are installed over a plank battening system laid over a subfloor.

Are floor joists required for a loft conversion?

Remember, loft conversions design professionally comply with building regulations and rules established for floor joists. Floor joists strengthen your loft and add to your safety. At the same time, they are in accordance with UK’s building regulations.

Can ceiling joists be turned into floor joists?

Because ceiling joists will almost certainly be considered inadequate when it comes to turning them into floor joists. If you would like to discuss the best way to go about a loft conversion then talk to us about loft conversion design and planning. Can Ceiling Joists Be Turned Into Floor Joists? In short, no.

How to choose the right floor joists for your home?

Remember, the new floor joists you choose must be larger than the existing joists. The existing walls can support new floor joists if they are adequate. Otherwise, you have to focus on steel or timber beams for additional support. Make sure the steel or timber beams are adequately provided with fire resistance.