We've had a quote to board the loft. The idea being we can banish the kids up there for gaming with their mates and we get some peace. Down the line we might put a velux or two in.
We got thinking about how cold it would be though. What do tyou need to do to keep it warm and insulated? All googling gives me is normal loft insulation details.
You probably need a full on loft conversion rather than just boarding out the space if you want to send a bunch of growing teenagers up there. Ignoring the fact it will be freezing in winter and roasting in the summer most loft spaces use fairly small timbers to support your ceilings. so they won’t take anything like the same load as the floors in your house before they bend/fail.
Yeah, the loft space above the insulation is fairly obviously massively affected by the external temperature of the roof or sun shining on the tiles. Probably similar to an unshaded/unheated conservatory that's habitable for about 2 weeks per year. You'd need to insulate the underside of the roof too, but not that horrible spray foam.
It is either a full conversion, or nothing. I have increased our insulation to 300mm and raised the boarded section on loft legs, but it is no way habitable. Storage, yes, but no way is it a living space. What access would you use? If we have the loft hatch open in winter, the warm air gets sucked out the rest of the house in minutes.
100mm wood fibre panels between the roof chevrons. Add 100 x 60mm cross beams with 100mm cotton/lin/hemp panels between .Screw on 66mm polyurethane panels. Total is about R=9, pretty cosy.
The guy told us their system is testing up too 500kg per sq m, and we'd have a new ladder put in.
Isn't that just the load rating of the loft leg system they use to carry the boards? It would assume that the existing timbers can also take that load which, as has already been mentioned, isn't a given.
How big is your garden? You may be better off buying something like this if you have the space...
https://hullypods.com/product-category/pods/skipjack-pods/
...and probably not much dearer as you'd need to put a proper power circuit into the loft space too.
Far safer than a load of kids stuffed in a bodged up loft space. It'll be fine until it isn't and there's a fire downstairs and they have no means of escape.
The guy told us their system is testing up too 500kg per sq m,
Thats the elements they've added - not the house they've added it to. Ceiling joists (you're standing on a ceiling not a floor when you're in a loft) are typically specced at a rate nearer to 25kg/sqm
If you're looking to insulate the loft space get good advice (not advice from someone with their own product to sell) as not all buildings are the same and the loft/roof is an integral part of how the whole house functions in terms of ventilation. So preventing that airflow by insulating can either have knock on effects for the house as a whole and/or trap moisture around the roof timbers and create problems with rot - which you won't be able to see because you've covered everything.
Some people get into bother when they come to sell where things like spray insulation has been used in a loft becuase the roof can't be inspected for the buyers mortgage valuation
Agree with the above - the loft is cold because its outside your house. If your loft is warm, thats heat thats leeching out of the house.
You can board it out and make it suitable for storage etc buts its never going to be warm and habitable unless its properly converted, I.E. incorporated into the rest of the house.
My loft space is absolutely roasting in the height of summer and icy cold in the winter.
There are a few months a year when it's quite a nice temperature but even then it's full of annoying beams holding the roof up.
The idea being we can banish the kids up there for gaming with their mates and we get some peace.
Yep it's no where near that easy I'm afraid.
As already said the ceiling joists for the rooms below will have been sized to hold up the ceiling plus a little leeway and no more.
(I've seen ceilings that you couldn't even overboard put another layer of plasterboard underneath without the joists sagging a couple of inches!)
Even just boarding for storage isn't that simple - think of the weight of the boards alone and then add the weight of what your putting on top.
You need to get up there an measure the joists, but I'd put money on them being undersized for what you want.
Then there's probably also the planning issue also (escape routes in the event of a fire).
My ceiling cracks when I move stuff around in the loft. Like others have said, the limiting factor is your joists, not the system they are installing on top. I added more legs to my raised floor as I think they made it worse by point loading the joists compared to when it was cupboard over minimal insulation.
i think the only halfway solution would be a loft room that isn’t built to regs as a bedroom, so still a lot of work and expense but doesn’t really add much value to the house.
From the age of 15 to when I left home at 20 my bedroom was in the loft with no window, and a ladder to get up there!
My dad fully boarded it out, put insulation in the roof and plaster boarded and plastered over it, electrics up there and carpet, it was essentially a proper room but no where near to building regs.
Unfortunately the roof was really low, so I couldn't stand up up there.....
The floor/1st floor ceiling sagged a bit over the years but it never came down!! Not sure if my dad added any joists or double up....
You need to be careful not to restrict air flow/ventilation around roof timbers. the temperature differential can cause serious condensation and rotten timber = new roof.
Might help to know the area size and approximate shape of the loft space(Im pants without a diagram) but some of the answers and downright horror stories seem a bit overkill to me.
Packing standard rockwool insulation between the joists then flooring the entire thing with moisture resistant t&g chipboard panels would be fine and i think strengthen the entire stucture by effecttively screwing it all together.
Weight. Again i dont think a few teenagers isnt going to be an issue as joists can take a lot of weight. And you have stiffened the entire floor.The joists themselves are going to be between 6 and 8 inches deep. Be they floor or intermediary floors/ceilings even 2x6 with floorboards all screwed together you wont have to be concerned about stiffness.
The joists themselves are going to be between 6 and 8 inches deep.
sure about that?
Pink insulation down on the floor, including the area under the bit. You can see we've put the loft boards down.
This is the same as normal insulation in the attic. We then put boards up the wall with polystyrene insulation filling the gap between the back of the tiles and the edge of the roof joists.
We were lucky as we already had two Velux in there. But plasterboard over the insulation, and you have an art studio.
It's not hot, but a simple air heater keeps the place fine for painting. In the summer, it's actually nicely cool all over the Velux window. Job done. Oh! We also put some flooring down because it was cheap.
- You nail the floor panels down
- You nail the plasterboard up
- You slot the laminate flooring together
- We put some lining paper over the + boards just to cover the seams
floor.The joists themselves are going to be between 6 and 8 inches deep.
How would you know?
some of the answers and downright horror stories seem a bit overkill to me.
My dad was an architect, my FIL was a builder, my BIL is a builder and I've renovated and sold a few houses. What would I know?
My dad was an architect, my FIL was a builder, my BIL is a builder and I've renovated and sold a few houses. What would I know?
Probably not as much as your dad , FIL and BIL - but I'm sure its relevant somehow to the knowledge you have on a complete strangers house with no other data about his house to go on other than it is indeed a house.
How would you know?
I googled it 😀
That said i agree that joists in houses can be subjective and for example my own home 0 115 yr old Glasgow tenement, the joists are about 7" or 8"
In another example of two houses myself, a friend and a wannabe builder(along with bringing in tradesmen to do steel rsj work/electrical/plumbing etc) but the rest of the fit out, inc taking a cellar and completely fitting it out into a basement flat, with everything that entails from sealing walls, then wall framing, stud partitioning of rooms, sheeting and boarding the walls and ceilings post installing insulation and Quitex** sound proofing(looks just like cat litter)
Digging out, leveling then laying a concrete floor which was then overclad with a floating floor and underfloor heating
So I've done a bit of building work, but my understanding of how strong floors are comes from the deadening we were required by law to install.
Rooms were about 4mx4m(or a bit bigger ...hold on ill work out approximate weights.
Now mind this is all signed off under Building Control, and we're following requirements.
Each of the spaces between the joists needs filled to a minimum depth of 50mm
A bag of quietex is 20kg, and im using 2 bags per length of joists, i think were about 400mm centers. 4x4m is about 9 or 10 center spacings, each filled with 30-40kg. PLUS the weight of 18mm board the deadening sat on, plus the battons that supported the board and entire deading, is the best part of 400kg.
And because its a basement, there is the weight of the upstairs neighbour. Those joists were about 9" or 10"
This remember is worked out by the manufacturer of the deadning and building control. If it was wrong or outwith the specs of weight etc they simply wouldnt sign off on it.
-- in my own flat i know the joists are 7"-with 1" thk pine flooring over them. One of the rooms is my workshop containing my tablesaw at 120kg, planer/thicknesser at about 90kg, bandsaw,pillar drill,drum sander, morticer,workbenches plus a hell of a lot of hand and power tools is probably another 100-130kg, plus myself at another 85gk(ahem) Again about 400kg.
Think of it another way. Xmas. house full of friends/family. 7, 8 people in a room. So whats that weight wise, going on 4M/4F is going to be about 600kg, plus the weight of all the furniture- given the average settee is 60kg up to about 100kg.
Im sure we've all been at big parties that might have a dozen people sitting in the one room.
Or how about you stand with 3 friends huddled together in the center of the room, Keep within 1sq meter. Thats at least 1/4ton 250-300+kg in that spot. Thinking youre all at risk of suddenly falling through the floor is just a tad of a stretch of the imagination.
I think the loft space can take it.
It seems your experience is based on floor joists, and not ceiling joists. Big difference…no loft in a basement conversion, only floors!
They are certainly not designed to be fully load bearing as habitable rooms, for new builds they are designed for 25kg/m and a 90kg person.
Three friends huddled together in the loft, many ceilings would crack, and a couple of jumps together and I expect you’d cause quite a bit of damage or go through if in the middle of a span.
Almost all loft conversions involve strengthening the floor first.
dyna-ti remember that in England their roofs are often made of matchsticks with no sarking - just trusses , membrane and tile .....
good chance if its modern its load rating is terrible..... but if its older then it can probably take it - but if its too old - it probably cant. there is no standard.
im in scotland in post war ex corp house and my roof has 10 inch joists which really hurt when my lazy architect didnt engage with the engineer ( i was already paying for) that the extension joists had to match existing roof.
Well it sounds like the teenager plan isnt a goer. I suppose best to just not take a chance.
surprises me though the numbers.
I know aa 10' long, 6x2 on its edge can take considerable weight(150kg in the center of an unsupported board before snapping). But its not a single plank, but rather a lot, in parallel, and all screwed together into what is effectively a single unit. So from that I'd have thought it could take a fair weight, but consensus says otherwise, so best go with that
I know aa 10' long, 6x2 on its edge can take considerable weight(150kg in the center of an unsupported board before snapping)
I don't think anyone is doubting that. But it's possibly completely irrelevant if the OP doesn't have 6x2 joists!