Steel ring beam installation for timber frame - how hard can it be?

[Great_scot_selfbuild]

So we're getting quotes in for a steel ring beam for our timber frame to sit on. The design structure is quite straight forward and it will sit on screw piles. I'm an engineer and familiar with designs that come with torque specifications on every nut and bolt; I'm not expecting this of the ring beam. The design and connections are straight forward, and we will be measuring prior to manufacture in order to get the fit correct. I'm looking at working with my builders to install the ring beam and the block and beam floor in order to save some serious money (quoted c.15k installation).

 

Has anyone done this before? when steelwork is bolted to a concrete foundation, is there a torque setting expected, or is it as basic as I'm expecting on a building site?

 

Is there something I should be considering? The task isn't technical - the technical bit is all in the design and measure before manufacture; the building control inspector is looking at the build matching the SE-specified design.

 

TIA

[Alan Ambrose]

Well that sounds an interesting project. Torque settings, to me, suggests a rather finer level of engineering sophistication that I associate with residential construction. Maybe steel frames for skyscrapers would? But I suspect not.

 

>>> Is there something I should be considering?

 

Well obviously the thermal detailing is hard around structural members that are good heat conductors. I expect some marmox blocks somewhere involved as a compromise. You’re happy with the expected life of screw piles?

 

Sounds a great project, have a drawing or two?

[Gus Potter]

22 hours ago, Alan Ambrose said:

You’re happy with the expected life of screw piles?

Take this on board. Ensure your research is sound.

[Gus Potter]

On 12/06/2025 at 21:25, Great_scot_selfbuild said:

So we're getting quotes in for a steel ring beam for our timber frame to sit on. The design structure is quite straight forward and it will sit on screw piles. I'm an engineer and familiar with designs that come with torque specifications on every nut and bolt; I'm not expecting this of the ring beam. The design and connections are straight forward, and we will be measuring prior to manufacture in order to get the fit correct. I'm looking at working with my builders to install the ring beam and the block and beam floor in order to save some serious money (quoted c.15k installation).

 

Has anyone done this before? when steelwork is bolted to a concrete foundation, is there a torque setting expected, or is it as basic as I'm expecting on a building site?

 

Is there something I should be considering? The task isn't technical - the technical bit is all in the design and measure before manufacture; the building control inspector is looking at the build matching the SE-specified design.

 

TIA

Hope this helps.

 

If you are using ordinary bolts then here is a bit of info below: But if using resin anchors you'll often find the torque setting in the manufacturer's data, don't exceed these!

 

The main thing is to apply common sense. Don't let the bolts get dirty or lose the manufacturer's oiled coating or store them badly for example, don't add oil either!

 

 

Now in the table above we can see a typical torque for an ordinary bolt with a spanner 460mm long. For an M16 bolt we are looking at approximately 90 Nm. What does that mean on site?

 

Ok roughly 100 Newtons is about 10 kg. If the spanner was 1.0metre long then we would need to apply 9 kg to the end of the spanner to generate 90 Nm on the head of the 16mm diameter bolt. But say your spanner is 460mm long (0.46 m) or 18 inches roughly. The sum is 10kg / 0.46 = 22 kg applied right to the very end of the spanner. So very roughly imagine you lift a 25 kg bag of cement with one hand... get a feel for that and then try and apply the same force when bolting up.

 

For bolt groups you'll know that we tighten them in sequence, gently going round an tightening them in stages.

 

All the best with the project and post some photos if you feel able.

 

 

 

[saveasteading]

I used to build lots of steel buildings. Torque was a real thing but we were instructed by the steel designers not to be too technical about it, but to turn the nut until it feels tight and then one turn more.

As above, it is more important that the nut turns on smoothly and you are only tightening: not trying to close gaps.

 

Also , whether the anchor is solid is critical. I once pulled a resin anchor out simply by turning the nut on , and it never became tight. ( the anchor was by others, and the resin was missing the second part).

 

Steel in wet conditions with oxygen will rust and fail. What spec are you using to avoid this?

[Great_scot_selfbuild]

On 12/06/2025 at 23:13, Alan Ambrose said:

Well that sounds an interesting project. Torque settings, to me, suggests a rather finer level of engineering sophistication that I associate with residential construction. Maybe steel frames for skyscrapers would? But I suspect not.

 

>>> Is there something I should be considering?

 

Well obviously the thermal detailing is hard around structural members that are good heat conductors. I expect some marmox blocks somewhere involved as a compromise. You’re happy with the expected life of screw piles?

 

Sounds a great project, have a drawing or two?

Thanks - I’ve just received and posted as a separate topic about thermal bridging question.

[Great_scot_selfbuild]

8 hours ago, saveasteading said:

I used to build lots of steel buildings. Torque was a real thing but we were instructed by the steel designers not to be too technical about it, but to turn the nut until it feels tight and then one turn more.

As above, it is more important that the nut turns on smoothly and you are only tightening: not trying to close gaps.

 

Also , whether the anchor is solid is critical. I once pulled a resin anchor out simply by turning the nut on , and it never became tight. ( the anchor was by others, and the resin was missing the second part).

 

Steel in wet conditions with oxygen will rust and fail. What spec are you using to avoid this?

Indeed - I’m please to hear that the stuff I’m focussed on (a lot!) is the bits others would recommend.

 

The engineer initially specified everything (literally) to be galvanised, but then he has a tendency to over-spec. We’re having to consider carefully what we go for as galvanised vs. Zinc oxide. It’s all going to be well protected from the elements and I have to keep reminding myself that one of the alternatives was a timber ring beam (saw an example of a house using this), and so a well-maintained steel ring beam already has a far longer lifespan). Plus we’re not in a challenging environment (not exposed, not next to the sea etc.).

[Great_scot_selfbuild]

9 hours ago, Gus Potter said:

Take this on board. Ensure your research is sound.

The score piles is something I researched significantly and is actually the least of my worries with the ones we’ve gone for (Quadrabuild, aluminium alloy helical screw piles) and we’re in a good sand-soil location (the area around us used to be a sand quarry in the late 1800s and the plot was set out in 1908 but never built on). Ground tests reached ‘refusal’ at around 2 - 2.5m.

[saveasteading]

Re steel rusting.  I've seen completely wasted structures, usually indoors in an aggressive environment. But also steel that's been exposed to the elements for 40 years, with only red oxide paint, and it is still sound.... it wets and dries again.

But in or near the ground I'd say it should be rigourously protected. Perhaps galvanised, certainly painted, or both.  I have a lot of time for bitumen paint....easy to apply and then slurp more into the welds and corners. 

[saveasteading]

I can't remember why they were so against any use of torque specifications.

Perhaps the torque wrench reacted too readily to other resistances.  But overtightening appeared to be the main concern...does that damage the thread?

My feeling is that the torque wrench would remove the attention and "feel" that was more important.

Any Mechanical Engineers able to explain?

[Mr Punter]

Make sure your warranty provider and BC are 100% happy with the use of screw piles.

[FuerteStu]

56 minutes ago, saveasteading said:

I can't remember why they were so against any use of torque specifications.

Perhaps the torque wrench reacted too readily to other resistances.  But overtightening appeared to be the main concern...does that damage the thread?

My feeling is that the torque wrench would remove the attention and "feel" that was more important.

Any Mechanical Engineers able to explain?

In my experience, over tightening of bolts is the main issue in metal failure. Not only can it damage the thread on the bolt and cause it to fail, but the abrasion of over tightening can remove the protective layer around it causing another weak point. 

 

Torque wrenches are as much about preventing over tightening than they are about tightening to a minimum torque.

 

And don't even get me started on split ring washers and them actually increasing the failure rate of bolts. 

[JohnMo]

14 minutes ago, FuerteStu said:

In my experience, over tightening of bolts is the main issue in metal failure. Not only can it damage the thread on the bolt and cause it to fail, but the abrasion of over tightening can remove the protective layer around it causing another weak point. 

 

Torque wrenches are as much about preventing over tightening than they are about tightening to a minimum torque.

Your torque tighten, to ensure the bolt is stretched and is ideally mid way in the elastic range of the bolt or stud. This allows for changes of temperature, vibration etc and the bolt to maintain tightness of the assembly.

 

If you under torque the bolt is not in the elastic range of the bolt material and if subjected to cyclic fatigue will give a very early failure of the bolt. It will break.

 

If you over torque the bolt goes out of the electric range of the bolt and will stretch the bolt permanently, the bolt will yield. At this point you are applying almost no clamping force with the bolt.

 

Your correct tightening torque changes due

Bolt minimum dia

Bolt coating 

Threads being lubricated

Grade of bolt - 4.8, 8.8, 10.9 etc

 

3 hours ago, Great_scot_selfbuild said:

aluminium alloy helical screw piles

So you have dissimilar materials, aluminium and steel. You hot dip galvanise the steel structure, but be aware a strong galvanic corrosion can occur especially when wet between aluminium and zinc (galvanizing). If the top of the screw piles are steel no issue, if they are aluminium - ideally you need an insulated bolt kit, this will sleeve the flange holes and below washers, the flanges would need to have gaskets as well.

[Great_scot_selfbuild]

10 hours ago, Mr Punter said:

Make sure your warranty provider and BC are 100% happy with the use of screw piles.

Both are good with this. Thank goodness as it's essential (RPZs).

[Great_scot_selfbuild]

8 hours ago, JohnMo said:

So you have dissimilar materials, aluminium and steel.

Great point. I've been so focussed on errors elsewhere in the design detail I haven't yet asked how the designers proposed this will be protected against.

[Gus Potter]

On 14/06/2025 at 07:30, Great_scot_selfbuild said:

The score piles is something I researched significantly and is actually the least of my worries with the ones we’ve gone for (Quadrabuild, aluminium alloy helical screw piles) and we’re in a good sand-soil location (the area around us used to be a sand quarry in the late 1800s and the plot was set out in 1908 but never built on). Ground tests reached ‘refusal’ at around 2 - 2.5m.

Hiya.

 

There is not much for us enthusiasts to go on here.. I'm guessing as you have not told us much about the ground and so on. I've had a read through the thread and here are some of the things I am interested in.

 

Screw piles.. ok but if you have an element of sand coupled with a high water table that could significantly reduce the performance. 

 

Now if you have investigated the ground, say carried out some cone penetration tests then with a refusal at say 2.5m you might have some competent ground. Why have you ruled out sitting your ring beam on concrete piers for example? These could often stop at ground level and then continue in steel if need be. 

 

On 12/06/2025 at 21:25, Great_scot_selfbuild said:

So we're getting quotes in for a steel ring beam for our timber frame to sit on. The design structure is quite straight forward and it will sit on screw piles.

Ok but you'll have wind (horizontal load) on the screw piles. How do you deal with that force? Screw piles are not that great when subject to horizontal loading. I wonder how your SE is dealing with this.

 

Lastly always think about buildability,  the labour / material cost and how many Contractors may want to put in a price. Unless you are going to do it all yourself then this can often be critical to the budget. It's a hard fact that while you may be an Engineer and want to go down one path you may have to pay more for the privilage. 

 

 

 

[Great_scot_selfbuild]

2 hours ago, Gus Potter said:

Hiya.

 

There is not much for us enthusiasts to go on here.. I'm guessing as you have not told us much about the ground and so on. I've had a read through the thread and here are some of the things I am interested in.

 

Screw piles.. ok but if you have an element of sand coupled with a high water table that could significantly reduce the performance. 

 

Now if you have investigated the ground, say carried out some cone penetration tests then with a refusal at say 2.5m you might have some competent ground. Why have you ruled out sitting your ring beam on concrete piers for example? These could often stop at ground level and then continue in steel if need be. 

 

Ok but you'll have wind (horizontal load) on the screw piles. How do you deal with that force? Screw piles are not that great when subject to horizontal loading. I wonder how your SE is dealing with this.

 

Lastly always think about buildability,  the labour / material cost and how many Contractors may want to put in a price. Unless you are going to do it all yourself then this can often be critical to the budget. It's a hard fact that while you may be an Engineer and want to go down one path you may have to pay more for the privilage. 

 

 

 

@Gus Potter Thanks for your interest. As you can probably appreciate I’m burning the candle at both ends and haven’t yet found that elusive 30hr day that I need, so my input is often brief and only contains the essentials as otherwise every post would be worth of a blog. Which I want to do, but see earlier comment about 30hr day…

 

Not wishing to deprive the enthusiasts however, PSA a screenshot of the summary from our ground pile tests.

 

Screw piles because of tree root protection zones and the planning permission constraints. Even concrete piling would undermine the principle of our approval (and the principle of our approach - we have chosen to minimise our impact; there are no TPOs on the site, though once PP is given, they are all ‘protected’ - of a form).

 

As for lateral strength/support, the SE has included diagonals on the columns for the ring beam - one end is at ground level, the far end is about 1.2m above ground. There are about 70 piles/columns. Aerial photo of the site goes some way to demonstrate why I’m not concerned about the lateral wind loading. House is 9.5m, tree canopy is 30m.

 

Buildability. I’ve often found myself leading the conversation on this theme. Agree on all your points. I wish I was willing to accept lower standards.

[Nickfromwales]

On 13/06/2025 at 23:17, saveasteading said:

the anchor was by others, and the resin was missing the second part

Stuff of nightmares.....

 

A friend of mine rendered the outside of a bungalow, with a friend of a friend mixing for him. Got to the end of a long day, scratch-coated the 4 sides and seemed a productive day. When cleaning up my mate noticed a load of cement bags and asked why there were so many left over (assuming builders merchant over-delivered) only to find out he'd been laying on a very, VERY weak mix all day. Next day he went back to remove it all with a 4" scraper, but said labourer refused to come back and help for free as he'd "done his bit"......

[Gus Potter]

On 18/06/2025 at 21:57, Great_scot_selfbuild said:

 Thanks for your interest.

Good and interesting info. I'm not trying to poke holes in your design to be an arse.. but from what you have posted so far just it looks a bit bollocks and here is why..but let's start with the upside!

 

I do like how your building sits in the trees, almost Canadian design.. love it! 

 

Often when I design I discuss with Clients some of my "whacky" options.. in design it's good to know what the rubbish ones are and the ones that could cost a lot... so you can rule them out. Good design is often about ruling out what you don't really want and then you focus on the things you do want.. and then this lets you focus in on the viable options... prevents you later thinking "we should have done that! after the fact. Your screw piles are a classic case in point.. I think you have not done enough work and plumped for screw piles! I think you might be making an expensive mistake!

 

You don't need to take my advice but to be safe consider it and rule it out.. then you know you are making good decisions. You will kick yourself if you get it wrong and I turn out ot be right! It's not my money after all..

 

From time top time I act as a lead Engineer on a project.. it my job to make sure everything is safe (in the round but not checking everything roughly). but also that we control cost where I can, call that a soft skill! 

 

Now some Cients just want to "do their own thing" Is this you? @Great_scot_selfbuildand are you  happy to pay for the privilege. I'll run with that as an SE provided it is a safe design. But this often commands a higher design fee... and the construction cost will go up exponentially!  I suspect you have gone down one route and are blinkered! Take a step back and review! My gut feeling is that the design you describe is going to cost you a fortune once you get down to the detail. and getting folk to execute on site.

 

Ok you might be in Scotland? and feel reassured the you have an SER Engineer.. not always my experience when checking their designs! Check the fine print is my advice! Look to see how they shed design and cost liability!

 

OK to be be blunt.. being smart does not always increase the value of you property. In fact it can reduce the value! I think you are trying to be too smart! My gut feeling is that this will trip you up futher down the road and you will get totally pelted when the Contractors submit their prices! You will be lucky to find any good contractor who wants to take on your job! Look ahead and smell the coffee!

 

Ok so you have posted a table of SPT results. When we are at the concept stage we say if in sand take the SPT"N" number and divide by 10! take the top left of the table and divide the number by ten.. look at the rest of the table.. it follows the same pattern! makes you wonder what you have paid for! What is not included is any mention of how the ground may perform when laterally loaded for wind bracing!

On 18/06/2025 at 21:57, Great_scot_selfbuild said:

There are about 70 piles/columns.

Ok if that floats your boat and you have the money to indulge  then fine.  Feel free to spend! But I suspect your SE is playing along and giving you qualified advice. It may be because they percieve you to be an obstinate Client and not taking advice and not willing to pay for it! But further down the road you will need to put your hand and in your pocket for the pile wind bracing.. who signs that off.. who welds it.. @Great_scot_selfbuild you are heading for a hiding here!  Give your SE a call and discuss some of my points.

 

On 18/06/2025 at 21:57, Great_scot_selfbuild said:

for lateral strength/support, the SE has included diagonals on the columns for the ring beam -

Ok but have they shown any connection, welding /bolting details.. Also Screw piles perform less well under lateral wind load as thy have a thin shank.. This is something I would check. It smells like lots of cost and frankly bollocks at my end! 

 

@Great_scot_selfbuildIn summary I think you need to go back and review your design and start asking your  SE some questions! It all look decidedly expensive to me and loaded with risk (your risk) once you get into the detailed design!

 

If you asked me to review this design I would want to look at the ground, the ground water, see where the tree roots are to provide the structural tree stability and where the finer roots go to get the nutirients. I can see the idea where you want a house in the woods.. that is your starting point.

 

I think you need to understand this in more detail. your 70 piles with the bracing is going to be massively expensive and you'll struggle to find a builder who will do what you want... I would seek to understand the trees, the soil even if we need a heavier steel ring beam on piers the we need to look at piers / vs root damage etc. 

 

In summary my suggestion is pay someone 3.0 to 4.0k that can design this foundation for you properly so it performs structurally and protects the trees. If you pay that amount then the design will probably reduce the overall cost and in the round.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Gus Potter]

@Great_scot_selfbuild

 

Ok to add a bit. 

 

Let's look at this in terms of how the trees grow. I'll be simplistic but hopefuly this gives you insight.

 

Trees need structural roots... stops then falling over. They also need water and nutrients... the Tertiary roots. Now imagine you are knocking in 70 screw piles and in doing so you will compact the ground! The structural roots of a tree go deep, the roots that capture the water and nutrients are close to the surface as they have to compete with the other vegitation. 

 

Your design is complex (as you have made it that way yourself!)and  at the moment and I don't think your SE and you have understood all the implications.. you clearly don't understand how trees grow.. if you did then you and ergo your SE would not be posting on Build HUb!.

 

My feeeling is that you are going to spend a pile of money and not actually achieve your design intent. 

 

Loom at concrete piers (these will often take care of the sideways wind load) say as a first go, not compact the ground, let the rain water moist the soil, under the building foot print|.

 

On the face of it it's complex but once you get you head around the principles the solution is ofen remarkably simple..

 

I suspect that you have fallen into the trap of one foundation solution! Time to go back and review!

 

I force myself as a designer to do this as it's part of my day job.. sometimes I find that I have followed the wrong path.. but this gives me time to correct and learn before I isued a design..

 

 

 

 

 

 

[saveasteading]

All very interesting.

Background then serious suggestions.

 

This will overlap with what you already propose and others suggest above. Credit implied!

 

I sometimes  come  back from trade shows, all excited about a new product and way of construction.

I take some convincing and expect am a pain to the reps of most things.

There have been lots of these screws on show recently. 

 

But my career is based on build-ability, function and cost. Although qualified myself I always had an independent SE practice do the final calculations. That was also a reality check before construction.

Once new methods were established and proven I would tend to make it standard.

Often the SE would admit they hadn't  wouldn't have  thought of my proposal and didn't realise the cost/ buildability advantage. ie they were not contractors, aware of costs.

 

But the reality generally did not appear innovative to non industry persons.

 

To the point....

 

You are proposing a concrete ring beam good. I've seen another discussion with steel.   

 

I've looked at these piles for a decade or more. Mostly they appear to be sold through franchises of people who offer only this....ie not neutral. I'm sorry to say most of the reps don't know much.  Despite this I have tried to design solutions using them, but never selected them....on cost and function.

 

  I see them as good for temporary buildings on bog or shallow  landfill.

 

Issues? As the above correspondents. Plus the trees and wildlife can flourish under your building.

 

Your ground is OK. But the trees require foundations to about 2.4m.

 

My gut feeling is to build concrete pads (mass filled, easy and cheap) at all corners and about 10 intermediates. Span the perimeter between them with a concrete beam. Maybe down the middle too. This can be poured insitu or bought in ( I've done both, to suit the circumstances ). 

 

You can then floor out any way you like but I suggest beam and block. Perhaps planks. Test both designs for cost and access.

 

No wildlife below. No steel or other metal to corrode. The whole building solidly on good bearing and below tree influence.

 

This can still be regarded as innovative if that appeals, while not worrying the authorities.

 

Cost? Much the same as with screw piles. Maybe less because local builders can do this. It is a suitable  diy process too.

 

  But it will last 200 years, get building regs, be insurable,  be saleable. And not have trees, worms and rabbits flourishing underneath.

 

Questions and counter arguments welcome.

 

 

[SteamyTea]

On 20/06/2025 at 23:26, Gus Potter said:

divide by 10!

That will be 3,628,800

 

Factorials are used a lot in statistics.

 

On 14/06/2025 at 11:00, JohnMo said:

Your torque tighten, to ensure the bolt is stretched and is ideally mid way in the elastic range of the bolt or stud. This allows for changes of temperature, vibration etc and the bolt to maintain tightness of the assembly

Spot on.

This makes the choice of, number of, fitting of bolt important.

Bolts are not screws. Though screws could be designed to be used here.

 

Railway lines have to be tightened and loosened for seasonal temperature variations. This has come about as they don't have joints every few tens of meters.