Oak frame plate join?

[pike]

To give a little more detail, I'm planning on replacing the roof and one long edge and one short edge wall. The other 2 are already there and are brick.

It's a nearly flat lean to. 4.5m long by 2.5 wide. The current design windows are 2m high and 1m wide. I'm replacing rotted softwood which was about to fall on our heads, with kiln dried oak and c16 roof framing. The roof would be ply and onduline bitumous corrugation.

Thanks for the advice so far re: top plates and headers. Plenty to think on.

This is an early design. I'm looking at having the roof over hang but haven't decided exactly how to do that or worked out loads. Especially that side over hang on the plates which I realise might not be sufficient as is.

There are 1x2 and 1x1 oak windows stops going in. The glazing will sit inside the posts/plates but not rebated into it as the stops will hold them.

The solid areas are existing brick walls. Not all noggins etc are shown.

 

[bosshogg]

The cantilever of the lower of the two headers looks to be bigger than the amount within the frame dims, that being the case could you consider a weight bearing post as per this sketch

This would support for both cantilevered overhangs you propose on your roof...bosshogg

"I never teach my pupils. I only attempt to provide the conditions in which they can learn."
Albert Einstein (hammer)

 

[pike]

Hey bosshog, the overhang is 1m. Yes I think putting a post there as you suggest is going to be the way to go. The missus has just seen it and thinks it'd be perfect to grow clematis up..

 

[tool613]

If i where to build that in canada this is what i would do.

The joist over the post are well supported as it is oak. really the framing is what I call stick. for rafters spans and the over hang you would want min tuba 8" (this does not take into account insulation depth if a 4 season room)and have those can-leaver off the post to carry the fascia. What you show as blocking over the plates i would use as a flush beam(two laminated joist stock 8" spanning post to post) and hang(with joist hangers the intermediate rafters that are center span on the window openings. this will take the load of the roof and transfer it to the posts so the two plates are not loaded. do the post on the side overhang and you are good for structure . The brick wall will give you all the rack that the structure needs. This is base on soft wood SPF framing so an engineer would be needed to grade the oak here in Canada.

As to flat roofs. IMO there the best one to make if you want them to leak. they can be made to not leak just as a bucket can hole water. the best are pitched to scupper and hidden with a parapet.


jack

 

[pike]

Thanks Jack I really appreciate the ideas and info. Apologies it wasn't shown on my sketchup but that's exactly what I had planned to do regarding the intermediate joists, hang them on what you called a flush beam.

The flat roof I agree with but it's this way to keep it as it was originally and also continuous with an attached garage. The onduline seems to work well enough on that.

I don't know what "tuba" is but i think you're saying you'd spec about 2" x 8" joists. I was going for 6" but will consider upping them.

Carl

 

[pike]

Just a quick update for what it's worth!

I'm well on the way with this, and taking wip pics. The frame and joists are up except I am now wondering what is the best way to fix the overhang posts to the ground.

The two corner posts on the left of the above sketchup. I'm thinking I'll need to concrete them into the ground, but I'm a bit concerned given how wet it gets in the area. The back one will be out of sight and braced but the front one won't.

Anchor bases seem a bit flimsy (after a small failed test).

Any thoughts appreciated.

 

[kostello]

for the corner posts the standard practice is to set them on a saddle stone of some sort with a 3/4" stainless steel dowel that goes from the post through the stone and into the footing........................

 

[bosshogg]

Don't know if you can get an ground auger in there, but it would give you a neat clean hole for pouring in a concrete footing/pile beyond any water logged ground. However you choose a concrete base would be best, as for fixing the post, a saddle bracket

could be incorporated into the newly cast concrete (s/s would be best) Alternatively there Homebase sell or at least did sell a structural frame making series of brackets about the size you are looking for about 40x40, by a company named Woodloc...bosshogg

 

[pike]

Thanks kostello and bosshogg.

I think it's going to be a hand auger for me. I need the exercise anyway! I've already dug one of the holes but it's a bit wider than planned so I'll have to use shuttering and backfill around it.

bosshog, I picked up a couple of these to concrete in, but am having second thoughts.

It's probably just lack of experience but I'm tempted to drill a bracket in afterwards to avoid me lining it up wrong. I realise the best thing is to set it while the concrete is wet and I might still do, just worried about not getting it quite straight in all dimensions.

The back post won't be visible so I was going to use a 4"x4".

The front one will and is the 44mmx121mm dry oak so I need to either as you say, find a different size bracket, use dowells or maybe start with a 4x4 and join them together (ugly!).

Cheers.

 

[bosshogg]

I've set out the bolts for steel buildings out this way and now I'm going to tell you - on your sketch up drawing drop the centre of the overhanging post positions to ground level. In dimensions, set these centres, with reference to say the nearest external studs (remember two of them will be in line) With a stringline fixed along the bottom plates, of the frames, mark these on the ground (I used to use 9mm cord, and sprayed over it from above with engineers marking out spray, which you may have or can borrow/buy, then when you lift away the cord, you'r left with two biodegradable lines at right angle to each other) now deduct half the bottom runner/frame dimensions and you have the centre of the overhang posts. With the concrete poured, push in the brackets you have bought in up to that base plate, it won't sink or anything and should stay vertical etc. if you want you can prop them. Best leave the plate ever so slightly proud of the top of the concrete, so that water will run off, also put a bit of chamfer on the top of the concrete for the same reason. Here's a sketch -

Hope that helps...bosshogg

Imagination is more important than knowledge...
Albert Einstein (hammer)

 

[pike]

Thanks a lot for your tips and time bosshog! Really appreciated. As I had never set concrete piers before, I stopped doing what I had been doing for the rest of the build, and using my sketchup measurements as a solid start point. I see how it would be done now.

However, after being out working on it today and talking to the missus I've decided I don't need the "gable" end overhang. The front one is the key and the side would block sun light anyway as that is the south side. So I've just given it a small 250mm overhang instead. I've finished all the roof framing today and I'm going to get on with the ply and onduline tomorrow. I *will* take some decent photos.

I'm building decking around this so I'll probably need to set piers anyway once the building is done.

Thanks again.