SE preliminary drawings. Check them out

[pilsbury]

Got some preliminary drawings back from the SE for the structural elements of my loft conversion. A pitched roof dormer will be going on the rear left side (top left of drawing). Payment will be made should I wish to go ahead with the “proper” calculated drawings. Basically he says calcs have not been completed. So I’m assuming a best guess here. Anyhow, I asked the following questions and would be grateful if any of you can make any suggestions as to what else should be asked and also comment. Must say I wasn’t wowed with the effort and you’ll see some of my thoughts in the questions back to him:


1. The 3x 300x47 ridge beams will go right under the current ridge board? Will the centre timber be raised slightly to fit in the current roof pitch? 3 of these timbers seems a lot!

2. How does the new ridge beam link to the top of the “goal post”? An intermediate post? New ridge is 141mm wide, the goal post is 94mm

3. How do the posts secure to the current steel beam?

4. Floor joists to the front of the house are 220x63 @400C. Again, seems rather big.

5. Floor joist for the rear are 200x47. How will this difference in height translate to the floor?

6. What are the trimmer sizes around the stairs? Do floor joists come off these?

7. Has any thought been given to removing the support posts that sit below the ridge of the current gables?

8. I’m assuming this proposal takes into account removal of the member between the purlins

 

[pilsbury]

Here’s my scale sketch of current layout.

 

[RonnyRaygun]

I think most of these details will be confirmed in the final drawings. Often the details you are questioning (such as how the ridge beam will sit under the ridge board) are worked out by the architect.

Some of the simpler details are often worked out on site by the builder. The SE will provide details for the more complex details / connections.

I think he's done well to design you something that doesn't require steelwork. That timber beam is supporting a lot of roof and would usually be steel at that span. A steel member wouldn't be as deep so you might prefer that

I don't think the floor joists sound excessively big. If you can't get 63mm joists put in 47mm wide joists at closer centres.

If you are worried about the difference in height of the joists, put the rear ones in at 220 deep too.

It looks like a basic scheme design to give you some idea of the requirements should you wish to go ahead, but it sounds like he's done this "at risk" so maybe it's not surprising he hasn't put in a huge amount of effort. Sounds like if you decide not to go ahead he won't get paid for the work carried out so far.

 

[pilsbury]

Thanks for the reply. The SE was briefed as to my circumstance. Basically, no architect, no builder, no designer….. just me. A have a go hero and YouTube expert. You lot on this forum also play a big part! Hence me briefing if timber can be used, do so. I have to lug this lot into the loft myself.

 

[RonnyRaygun]

Thanks for the reply. The SE was briefed as to my circumstance. Basically, no architect, no builder, no designer….. just me. A have a go hero and YouTube expert. You lot on this forum also play a big part! Hence me briefing if timber can be used, do so. I have to lug this lot into the loft myself.

In that case you might need him to do more of the details which are usually done by the architect, or that a professional builder would know how to do.

Ask him to price in the additional details so that you have something to work from when you get started.

 

[pilsbury]

I’m expecting this will be included. He knows my situation and for £650 I’d be expecting him to come and give me a hand building!

 

[^woody^]

I'm just seeing diagrams of rudimentary scaffolds. Where are the raking shores?

 

[pilsbury]

I have no idea. As said, these are preliminary drawings before payment. If I want to go ahead he’ll produce the calculated drawings. Hopefully “raking shores” will be in there should they be needed.