The Walter Segal Method Of House Construction

[RichC]

Hi All,

I have an interest in the Segal Method of construction...

I mentioned this is a thread started by @Mischiefsmum, and following interest principally from @SteamyTea and @Ed Davies, I am creating this topic for further discussion.

Ed - I've been reading with great interest your A-frame house build blog, and admire the Segal principles that you've employed, reducing the foundations to plinths as a foot for the posts. I look forward to you contributing to this thread.

I must reiterate that I am a layman in this field, and anything I say should be taken with a grain of salt

 

I'll start off then with something that is concerning me at the moment. I don't know whether I'm putting the cart before the horse or not. I don't have my eye on a plot of land, but I want to get on with design, and drawing up some plans. Given the flexibility that Segal's method provides regarding provision for land slope etc, I'd be interested in people's thoughts regarding design first, then buying a plot second, rather than designing to 'fit' the plot?

I ask this because I am not going to be in a position to purchase land for at least 6 months, but don't want to waste time that could be put into design.

I look forward to your ideas.

Rich.

[SteamyTea]

Have you thought of making the design as modular as you can i.e. a living room is x times the area/length/width of a bedroom.

Then think about things like kitchen and bathrooms as these take standard sized 'stuff'.

Thinking of standard stuff, see what sizes of timber and sheet are easy to get hold of.  Don't really want anything that needs to be made special.

And, if you are fairly practical, or even f you are not, how about making a scale model or 3.

 

[ProDave]

I doubt you could make "design before the plot" work much beyond concepts as the final layout of a house is usually so site dependant.  Even more so when you start throwing in slopes, obstructions, views, orientations, neighbours etc.

 

We looked at two plots before buying one, and the house on each would have been totally different.

[joe90]

Before I had a plot (just dreaming really) I went through lots of designs to get a grip of what I wanted and their sizes, also orientation. It took me a while to find what i would be happy with. Luckily we didn’t have to compromise as the plot we built on was large enough to allow what we wanted. Create yourself a list  of “would like to have”,s.

[ProDave]

For us it was plot orientation and size.

 

The other plot was narrow but deep, the one we bought was wide but not very deep.  Then the orientation. The other plot was on the north side of the road, so the challenge was getting sun into the living rooms and having a sunny bit of garden without feeling like you are living in the front garden.  the plot we bought is on the south side of the road so the back of the house faces south, so much better and easier.

[Ed Davies]

Difficult one. I certainly had a reasonably clear idea of the design of the house before I fixed on the plot so maybe the house design overly restricted the plots I took seriously. The final design would have fitted, give or take mirroring about the north-south axis, on three of the four plots I went as far as significant discussions with the vendor about. But then my intention from the start was to have a lot of solar [¹] so it was a basic requirement to have pretty unobstructed sky in a generally southerly direction so my east-west axis, south-facing design was likely to fit. The one which was a bit awkward was on an east facing slope.

 

Even if you leave picking the exact house layout until you have a particular plot in mind there's a lot you can usefully think about regarding construction methods, heating systems and general house requirements in the mean time. Having a few “contingency” sketches of possible room layouts might help in making the plans a bit more concrete without getting overly committed to particular ones. I'd suggest that Segal-like construction fits this approach quite well but not uniquely so.

 

[¹] including solar thermal which is a bit more awkward than PV to ground mount any distance from the house.

[stephen margerison]

Sorry but you have missed a massive possible problem, the planning dept !    

don't waste money, 

ideas are good , but plot comes first. the planners altered my plans 14 times, I was so frustrated, I could easily said you design the so and so house !

regards,

Stephen

[SteamyTea]

Take it you have seen this site.

https://www.irishvernacular.com/making-timber-frame.html

[Ed Davies]

I hadn't seen that irishvernacular site. At a quick glance I mostly like it except for the brackets at the foot of the posts (image 6: Foundations - pouring) as they leave the bottom of the post flat on the ground with a bracket up the side which could trap water.

 

Mine sit on steel brackets with a flange going up the inside of the post. Like so. They were a pain to do and, in retrospect, I'd have drilled through the wood and steel in one operation then put cold galv spray on the steel before finally bolting them up but they do reasonably a good job of keeping the posts' feet dry.

 

Simpson Strong-Tie do brackets like that off the shelf though they're a bit smaller than mine, probably intended for garden rooms and the like.

 

The irishvernacular bod says to put the brackets in while the concrete's still wet as “drilling fixings into set concrete is a real pain”. Actually, even with a moderate SDS drill it's not that much of a problem except that it's often difficult to get the hole exactly where you want it as lumps of aggregate will move the tip until the hole is established. The chap who did mine made a pretty good job of setting the brackets out but still some are 10 to 15 mm off the nominal position so in one or two places the spacing between the posts is 30mm off nominal. This made spacing the I-beam studs between the posts on the west gable to support the edges of the OSB sheets properly a bit of a puzzle.

 

Doing it again, I'd follow the “standard” Segal method [²] of putting the post-and-beam structure up with the beams between the posts cut to the right length and fitted in place so all the dimensions are right then wack things as need to fully square it up before drilling the bolt holes.

 

[¹] I got a contractor in to do the concrete foundation blocks. I got them to fit the brackets precisely because I though drilling the concrete would be a pain.

 

[²] As described in, e.g., Out of the Woods: Ecological Designs for Timber Frame Housing by Pat Borer and Cindy Harris.

[SteamyTea]

34 minutes ago, Ed Davies said:

The irishvernacular bod says to put the brackets in while the concrete's still wet as “drilling fixings into set concrete is a real pain”. Actually, even with a moderate SDS drill it's not that much of a problem except that it's often difficult to get the hole exactly where you want it

Probably due to my toolmaking background, I would make a jig^[1].  Basically a steel plate with holes in it that you stand on while drilling.]

If I was building a place, I would make lots of jigs, and a decent surface table^[2] to build on.

 

^[1] Basically bits of plate, box and angle

^[2] Just an adjustable trellis table on paving slab that is easily adjustable to get level

[RichC]

@SteamyTea Yes! I have read and re-read his website. It's an interesting build. As Ed says, there are things that I'd change, particularly the roof and how it ties into the walls. I understand what he was trying to achieve though, and he cleverly avoided creating an attic truss roof, but at the expense of any overhang at all which gives the house a little bit of a bleak look. He did stick quite faithfully otherwise to Segal principles.

 

The foundations and the brackets are something I keep coming back to. I like the idea of the posts being tied down to something, and I understand why you did what you did Ed. I don't like the idea of the posts resting directly on the foundation pad either. Segal specified that the pad should have a slight slope on it to allow runoff, and then be capped with a paving slab. I wonder how many of those paving slabs cracked though....? The idea was that even an inexperienced builder could dig the foundations, so that even with a little error, the posts would end up in roughly the right place. However, you have to have some accuracy somewhere, and I wouldn't shy away from setting brackets into the concrete, and they would certainly be raised up.

 

There are many photographs of Segal houses being built online, but many of them are of less than stellar quality. I did find a website with a set of gorgeous interior pictures of one of the Segal builds in Bromley:

https://www.themodernhouse.com/past-sales/elstree-hill-bromley/

Hover over the picture and then click on the 'More Pictures' button that appears. It is very interesting to see the interior and how light and airy these houses can be, and the structural posts are all plain to see.

 

Rich.

 

[RichC]

6 minutes ago, SteamyTea said:

Probably due to my toolmaking background, I would make a jig^[1].  Basically a steel plate with holes in it that you stand on while drilling.]

If I was building a place, I would make lots of jigs, and a decent surface table^[2] to build on.

 

My thoughts exactly.

[SteamyTea]

4 minutes ago, RichC said:

and he cleverly avoided creating an attic truss roof, but at the expense of any overhang at all which gives the house a little bit of a bleak look

Overhang could be achieved with an 'add-on'.

Basically a pre-manufactured fascia, soffit and appropriate roof slope.  Maybe with built in guttering.

 

[RichC]

I just went back to look at the pictures of your build Ed. I see that you put the posts individually on the brackets. I wonder how practical it would be to use those if the whole wall was already pre-assembled before being lifted up onto the brackets. Would be disappointing to find out that the flange was a cm off....

...but as I write this I realise that that could be alleviated by aligning the flange in the same plane as the wall

Rich.

[Ed Davies]

The flanges on my brackets are aligned east/west, parallel to the ridge line, and I think [¹] they contribute significantly to the east/west racking strength of the house so you couldn't turn them through 90°. When the posts and beams were up but before I started on the roof the structure was quite stiff east/west but swayed a bit north/south.

 

[¹] Structural engineer specified this but we didn't, unfortunately, have a lot of discussion about it.

[SteamyTea]

Why don't they/we design a hinged bracket.

That way you can assemble a wall, jack one end up onto the hinges, bolt/screw in place, then lift the wall vertical.

Then some sort of locking plate on the bracket.  Maybe 3 sided box section instead of two upright plates.

 

Edited February 12, 2020 by SteamyTea

[Ed Davies]

Hinging is sort of what I did. Still, specifically designing a hinge to be used once then sit unhinged for decades seems a bit odd.

[Jeremy Harris]

16 minutes ago, Ed Davies said:

Still, specifically designing a hinge to be used once then sit unhinged for decades seems a bit odd.

 

Just call it a pin joint instead of a hinge.  Pin joints are often used in big construction projects because they both make erection easier and also make the stress calculations simpler.

[SteamyTea]

15 minutes ago, Jeremy Harris said:

Just call it a pin joint instead of a hinge

I was really thinking about something homemade. 

35 minutes ago, Ed Davies said:

Hinging is sort of what I did. Still, specifically designing a hinge to be used once then sit unhinged for decades seems a bit odd.

May seem odd. But if it makes construction simpler, easier, safer and faster. A simple, cheap hinge, which could be removed and reused seems worth it to me.

I always think of you trying to move things into place, on your own. Though you have picked a design that has long lengths.

[Ed Davies]

1 minute ago, SteamyTea said:

A simple, cheap hinge, which could be removed and reused

 

Ah, right, I was assuming incorporated in the structure.

 

2 minutes ago, SteamyTea said:

Though you have picked a design that has long lengths.

 

Doing it again I'd have longer lengths, but thinner. E.g, instead of making up the purlins out of 3 metre or so long lengths of 145x245 C24 (or was it C16? I forget without looking - I do remember the posts were specced as C16 but I actually used C24 as that was what was available) I'd have used 3 off 6 or 7 metre lengths of 45x245 or whatever lengths of LVL staggered and bolted together. The ring beam for the floor has 13 metre lengths like that which I could move fairly easily with a bit of forethought.

[RichC]

With respect to the hinge / attachment to the ground discussion above, Walter Segal did not specify any form of brackets at ground level, as I think I may have mentioned. However, he did specify that a plate of lead be laid underneath each upright post. The idea being that eventually the weight of the building would force the lead into the endgrain of the post and protect it from rot.

I would love to go and see some of the existing buildings in London and see for myself if this is evident in the construction, and see how well those posts have stood up to water damage over the years.