Q for Marckee or other DIY/building nerds


#1

So my loft space essentially looks like this:

Am I ok to put some wooden pieces horizontally across the ‘V’ pieces (trusses?) and then run some loft boards along to make some shelves? Do I need to be particularly concerned about the weight of stuff that I put onto them?

@marckee


#2

here’s a better pic of what I mean. Looks like other people have done it (appreciate that doesn’t mean it’s a good idea)


#3

Should be OK

(I have no building qualifications)


#4

cheers NV!

Just to note, the ‘trusses’ are much more like the second photo thank the first, they’re pretty solid.


#5

Don’t ask Kasabian round for a brew.


#6

Seems to be a pretty common thing to do:

http://www.wickes.co.uk/Loftleg-Loft-Ledge-Kit-for-Trussed-Roofs/p/114291

But I guess don’t go crazy with the weight.


#7

(September 2017)
Builder: I can’t imagine why you thought this was a good idea, mate
jontosh2001: But a bloke on the internet said it was OK!


#8

ahh cool, hadn’t seen that. Quite expensive for what it is though seeing as I have maybe 16 gaps that I want to utilise, good job I know how to use a saw and screw wood together!


#9

Is your roof made up of trusses, or is it made up of rafters, purlins and struts?

A truss is a braced unit, set out at a close spacing, eg 600mm - similar to the second photo, and found in most roof spaces after about 1960, whereas if it’s a rafter, purlin and strut roof, the struts will be at much wider centres as the purlins take the load onto the party/gable end walls. The latter is typically found on older properties.

I would say that you’re okay to do what you want if your roof is the trussed type, but I would speak to a structural engineer if it is the other type.


#10

Yeah it’s trusses similar to the second photo. like this:

cheers!


#11

Yeah, I would put the shelves between the tension and the compression webs, rather than between the compression web and the top chord.

Obviously, be sensible with what you store up there - I wouldn’t go chuck lumps of lead or paving slabs on them.

Before you do it, I’d make sure that you’ve insulated the loft space properly (double roll it) as the shelves might make the eaves difficult to access, and then use spacer bars and boards to board over the section above the bottom chord between the tension webs, to act as a walkway.


#12

Hi @marckee, I also have a question about roof loadings.
My SE said that the only load the wall downstairs wall being removed was supporting was the wall above (100mm brick, 2 sides plaster) with floor joists, ceiling joists and rafters spanning parallel, only a dead load, and no live load (as is just wall above). But my question marckee is, is there not some load to factor in from the attic ceiling, that is going to the wall below, and then subsequently down to the wall being supported by the new beam? or is it negligible?


#13

it would probably be so negligible actually if everything runs parallel, like literally the weight of a brick or something idk whatever


#14

yep I’m going to leave a gap each side in the shelving for eaves access and make a walkway. I’m hoping to get an electrician at some point to extend a ring into the loft so I can improve the lighting and put some ceiling speaker in rooms as we redecorate.


#15

That is a bit unusual. Typically, a dividing wall would also be taking the load of the floor joists and roof joists. From your sketch it looks like the joists are running parallel to this wall though, meaning that no load comes down through it, apart from the self weight of the wall above. In which case, a much smaller beam would be needed if the wall was to be knocked through.

A quick way to tell which way the joists are running is that the floorboards will be perpendicular to the them.


#16

Hi, yeah the joists run parallel, had a look myself and floorboards perpendicular. But normally in this situation, with an attic and wall above, you would be looking at factoring in floor and roof joists? (I guess any other loading from roof would be supported by rafters, so only factored in if messing with external wall?). Cool, cool. Thanks @marckee


#17

Yes. In a typical terraced house or inter war semi, the floor and ceiling joists span front to back, with the dividing wall between the living room and the dining room picking up the load at the mid-point. The rafters usually bear onto the external wall, tied by the ceiling joists, therefore spreading the load across all of the load-bearing walls.

Typically, removing the dividing wall will therefore require a beam of about 280mm depth to cope with the load.

But if this dividing wall is not carrying anything other than the weight of the wall above, then it can be much smaller.


#18

Very Grand Designs…


#19

Thanks marckee, yeah small beam, just a 152x89x16


#20

they are currently taking the load of an entire roof

Im sure they could also take some grot mags and games workshop merch