boarding a loft

[steptoe]

yes, would be using 270mm legs to allow me 340mm insulation, 100mm joists, so 370mm clearance in total.

have only seen legs at 170 or 270,

if I used timber would have to screw it across the inward truss angle, and probably a small upright in the middle, would that not help with a triangulation effect?

 

[Rob_the_rich]

yes, would be using 270mm legs to allow me 340mm insulation, 100mm joists, so 370mm clearance in total.

have only seen legs at 170 or 270,

if I used timber would have to screw it across the inward truss angle, and probably a small upright in the middle, would that not help with a triangulation effect?

You might spend all afternoon screwing timbers to your joists, getting them nice and tight, then go in the bedroom and find all the plasterboard nails have popped the plaster everywhere, with 10 mins before she gets back.

 

[steptoe]

You might spend all afternoon screwing timbers to your joists, getting them nice and tight, then go in the bedroom and find all the plasterboard nails have popped the plaster everywhere, with 10 mins before she gets back.

:slap

thats would be nothing,

she is used with a lot worse,

she once came back from shopping to find no kitchen, except a sink, it sort of stayed like that for almost 6months, 

upstairs ceiling will be getting skimmed at some date in future anyhow, bloody stupid '70s artex and coving,  :|

you know what, the more I think about it, unless anyone can come up with some sort of structural reason why not to, I'm going to revert to the 4x1 across the trusses with an upright in the middle, I'm failing to see how this would be any more loading than legs directly on the cross members,,,

and, it would be a damn sight easier to do, never mind cheaper.

 

[Rob_the_rich]

 I'm going to revert to the 4x1 across the trusses with an upright in the middle, I'm failing to see how this would be any more loading than legs directly on the cross members,,,

and, it would be a damn sight easier to do, never mind cheaper.

would the upright be in the middle of the span? or over a spline wall? I assume span, 2 at thirds would be better than 1 in the middle. just use up all the off-cuts, more the merrier.

 

[steptoe]

its only on a 6' span, be about 7' between the two trusses tbh,

ye, I could put 2, or even 3 uprights in, I could even buy an extra length simply for that reason,

just priced the timber, comes in at under £30 for 3x2, a bit less for 4x1, timber yard is <5mile from me,

legs are costing closer to £60,

 

[Sharpend]

There's a reason why timber is used in construction, I can't imagine plastic lasting the course, won't it go brittle over time and be susceptible to breakage? 

 

[OnOff]

I noticed a massive difference when I fitted 22mm boards being used to 18mm before that fixed with good old angular ring nails. Mind you my centres are 400mm. The whole floor just feels more solid. Strength wise though pretty sure it should be 22mm at 600 ctrs. Worth future proofing it in case you ever want to do anything else with the loft.

As for screws I use nothing but Spax ones:

http://www.tradefixdirect.com/nails-screws-fixings/screws-accessories/nails-screws-fixings/spax-countersunk-pozi-screws/spax-flooring-screws-4.5-c-60mm?gclid=CIvlk6auusoCFQUewwodRzgOjA

You'll never have another squeaky floor using them. They do exactly what they say on the tin box. Even used them on some existing downstairs floorboards that are fitted with cut nails and it's sorted those squeaks.

 

[steptoe]

ok, timber it is then, across the trusses, with 22mm boards,

any preference between 3x2 or 4x1 ?

both seem to offer close to the same strength, 3x2 being slightly heavier, but having a larger surface for getting the screws to hit,

so less chance of splitting = more secure floor = more structural rigidity [?]

 

[Evans Electric]

I did  job last week for the Chippy , make safe some dodgey connections before he floored the loft.

I remember him saying it was cheaper for him to cross batten the loft instead of the stilts , which seemed very expensive , and he used the thinner boards as it was storage only .  He also drove a screw straight  through the sheets , the usual type screws that builders always use , instead of us raised on 1 1/2" X 8 s .

 

[steptoe]

thanks Deke,

purely storage,

headroom would be too little once I raise the floor, plus, I dont think structurally the trusses would take any serious use,

as above, the usual carp of xmas decs, suitcases etc

ye, 1&1/2" 8s, its the staple of a spark I think, 

will get myself some 2" drywalls though for screwing the boards down with,

still unsure of whether to go with 4x1 or 3x2 tho, will prob decide tomorrow when I get to timber yard,,,,,

I'm leaning to 3x2, just worried about even more weight, but thinking the structural rigidity will more than compensate, will be able to run some angles and more uprights on the 3x2 easier.

 

[Rob_the_rich]

ok, timber it is then, across the trusses, with 22mm boards,

any preference between 3x2 or 4x1 ?

both seem to offer close to the same strength, 3x2 being slightly heavier, but having a larger surface for getting the screws to hit,

so less chance of splitting = more secure floor = more structural rigidity [?]

3x2 deffo. Are the trusses on top of the ceiling joists? or attached to the side? if to the side, no need for angled cuts, oversail it and screw through the side. Definitely pilot drill first bit of wood if screwing near its end, 75mm 8s should do. Could oversail the offcut props too, but might squidge the insulation.

also agree 22mm boards if price nearly the same as you say. Although sounds like 18mm is enough.

 

[Sharpend]

I generally find 18mm is fine for general storage, even walking over, but if you are planning on jumping around then you should go 22!

 

[steptoe]

3x2 deffo. Are the trusses on top of the ceiling joists? or attached to the side? if to the side, no need for angled cuts, oversail it and screw through the side. Definitely pilot drill first bit of wood if screwing near its end, 75mm 8s should do. Could oversail the offcut props too, but might squidge the insulation.

also agree 22mm boards if price nearly the same as you say. Although sounds like 18mm is enough.

I need 6 boards, 8'x2' , so not a massive area, about £1-50 difference at my local yard, 2 mile away, so 22mm it is then,

I'm unsure what you mean by are the trusses above the ceiling joists,

they are the same thing, from what I understand, its trusses I have, not joists, maybe I dont understand the terminology right.

 

[Rob_the_rich]

https://www.youtube.com/watch?v=PvZEwTe_n3w

Tyrone says 22mm :innocent

 

[Rob_the_rich]

I need 6 boards, 8'x2' , so not a massive area, about £1-50 difference at my local yard, 2 mile away, so 22mm it is then,

I'm unsure what you mean by are the trusses above the ceiling joists,

they are the same thing, from what I understand, its trusses I have, not joists, maybe I dont understand the terminology right.

ceiling joists have plasterboard under, roof trusses are the diagonals from eave to apex. in older builds the trusses were attached to the side of the joists on the wall plate and sailed over to create the overhanging eave. Newer builds have an A-frame with plates over the joints to hold it all together.

 

[Evans Electric]

Stepps , don't forget you can't always get long boards up the hatch .  

AND I heard recently that loft lagging in an average semi only saves about £30  a year .    So not as important as the insulation companies would have us believe.

 

[Rob_the_rich]

ceiling joists have plasterboard under, roof trusses are the diagonals from eave to apex. in older builds the trusses were attached to the side of the joists on the wall plate and sailed over to create the overhanging eave. Newer builds have an A-frame with plates over the joints to hold it all together.

oops I meant rafters when I said trusses. "Trusses" used to hold up the purlins, but the term is now used for prefab a-frames.

 

[steptoe]

ah, ok,

then I have pre-fab A frames,

I call those trusses,

I call traditional roofs are made using joists and purlins,

sorry,

my English terminology isnt always correct,

 

[kerching]

ah, ok,

then I have pre-fab A frames,

I call those trusses,

I call traditional roofs are made using joists and purlins,

sorry,

my English terminology isnt always correct,

Well up,here they are known as Trusses!....my mate is a Builder and was explaining 'diminishing trusses' on a recent jub we did

https://www.google.co.uk/search?q=roof+truss&rlz=1C9BKJA_enGB590GB590&hl=en-US&prmd=isvn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj7j-S687vKAhUJsxQKHe5vBq8Q_AUIBygB#imgrc=_

i remember last Century being at College and having to 'take moments' on a roof truss to,calculate whether the members were in tension, compression or redundant. Must admit to not having used that skill very much since1975

just saying

 

[steptoe]

ok, so this is what I have

ww.classictruss.com/art/truss_configurations_terms_defined.gif

and, it does appear to be a truss, as also called by Kerching,

#maybe its yet again one of those things where something is called something in the North,

and called the wrong thing in the south, because  they are too thick to know any better,    :C