Any structural engineers on here?
 

I am in the middle of my extension and building control have pulled a small issue with my roof and want to see either a calc to say what is built is fine or a calc to demonstrate how I will change it to comply.

My resident engineer has disappeared and is now not returning my calls lol ( yes he's been paid)

Should be no more than an hours work but just looking for somebody trust worthy to do it for me?

Many thanks

Alex

Re: Any structural engineers on here?
 

What is the issue mate?

There will always be differing opinions and methods.

Re: Any structural engineers on here?
 

I have a raised ceiling joist to give me some ceiling height to match the existing property but I haven't built it nhbc compliment with bigger trusses etc ...

The roof is still over spec'd and I have used grade 8.8 bolts and timber connectors but basically as it doesnt tick their boxes they want a calc to prove it.. Big shame IMHO the existing roof is built from smaller timbers without the over spec and yet it's still standing!!!

Not happy tbh!!

Re: Any structural engineers on here?
 

Sound picky tbh, is it a vaulted ceiling you've done? Some of the steelwork I've had to put in a roof I've just done had me baffled, I could've done the same with double 7x2's, massive over spec IMO.

I had to put a 10mm plate and 8x2 either side to create a flitch beam, bolted at 450mm centres, could bloody land a plane on it, Bco come to have a look and was there 2 mins, more concerned what size rafters I used, 7x2 generally means most extension roofs will be more than enough.

Re: Any structural engineers on here?
 

If you can tell me all the dims and send a few pics I'll have a rummage through our tank for anything similar. If there is something there then I'll pull the calcs for it too.
It won't be your roof cons but it'll be close enough as far as bco are concerned.

I need timber sizes, lengths of spans and centres. Could do with knowing the intended loadings inc what sort of ceiling you're intending on fitting.

Don't hold your breath though structures
Isn't my dept its more of something I dabble in. Before I send you anything though I'll have a charted structural engineer take a peek.

Alterntivly if you want to do it properly I can hand you our office number and we'll get it done by the book but you'll be getting a fee then that's for sure.

Re: Any structural engineers on here?
 

Morning All

Well by 7.30 this am they were in my inbox justifying what is built is A ok...

Hoorah.

he's a top engineer when he returns my calls lol :-)

Cheers for the option though owenski, I too use to dabble in structures but this is way over my head :-)


this is the roof in question.

https://fbcdn-sphotos-g-a.akamaihd.n...70740602_n.jpg

https://fbcdn-sphotos-a-a.akamaihd.n...70899905_n.jpg

https://fbcdn-sphotos-b-a.akamaihd.n...90182116_n.jpg

It does now have all ceiling joists in etc etc.

Re: Any structural engineers on here?
 

I see the issue raised by the inspector now.
The joists are just bolted through the truss's they're reliant on the sheer strength of those bolts and integrity of the timbers as opposed to directly loading the walling where all you'd need to worry about is the span and deflection.

:thumbsup: on having it cleared now though.

Re: Any structural engineers on here?
 

its why I used grade 8.8 bolts..... :-)

try shearing one of them buggers

Re: Any structural engineers on here?
 

Couldn't you have built a small purlin to take the load? Doesn't matter now as its passed.

Have they asked for any noggins? That will twist like buggery when it dries.

Re: Any structural engineers on here?
 

You intending on using the space for anything or will it just be a void/insulated?

Re: Any structural engineers on here?
 

the roof is now tied and strapped so wont twist too much and under the load of the tiles it wont be obvious anyway.

There will be loft space so I need to stick in an access door but this will be mostly just insulated and then storage on top.

The plan was to install a couple of purlins if it didn't pass but it has so yay.

Note to self.. build a house from scratch next time, not add a bolt onto to a wonky cottage from 1900 and frozen to death.

Re: Any structural engineers on here?
 

Just out of interest was it just the connection of the raised chord they were worried about or was it the eaves spread?

Re: Any structural engineers on here?
 

Eaves spread,

engineer said it will be fine now :-)

Re: Any structural engineers on here?
 

Yup, thats one of the repeat problems between engineers and building inspectors on all raised chord roofs......

And the best solution to satisfy the inspectors (other than trying to blind them with science) doesn't really work, and if it did, it would feck up your wall design....

Been round and round in circles with that one before.

Re: Any structural engineers on here?
 

If they are worried about spread at the eaves, couldnt it braced further up the apex as well? Not a problem if the space isn't being used?

Any structural engineers on here?
 

Yup,

Proper ridge member rather than a board...is a way to satisfy them, but clients always see that as OTT.

Re: Re: Any structural engineers on here?
 

Heard that before! Such a classic example of them not actually understanding the function of the structures they validate.

Re: Any structural engineers on here?
 

you mean like the 75 x 200 ridge beam I needed to use for my porch thats a whopping 3.8m wide by 2.5m?

https://fbcdn-sphotos-a-a.akamaihd.n...57566389_n.jpg

To be fair, I don't mind BC flagging stuff that they think is wrong, id rather that then let me finish it and have to re work it.

If I wanted a fully vaulted ceiling like my porch I would have been happy to put the ridge beam in but I didn't and it wasn't at the time needed for the main roof so we didnt fit one, its not that expensive tbh, but anyway.

The roof was built by an experience joiner and myself but all is good.. best get felt and battening this weekend :-) hoorah!

Re: Any structural engineers on here?
 

Another thing you could've done is add horizontal bracing midway between your ceiling joists and the ridge, with maybe some diagonals connecting the two rows, this would be insanely strong.

Or...buy manufactured roof trusses, the calcs and construction are done for you, order and fit, job done :)