Portal Frame Church?

[why_aye]

Hi 

 

I’ve stumbled across some very informative details on this forum with regards to portal frame builds and have a few questions that I’m hoping folk can help me with.

We are looking to build a new church building for our congregation of +250 folk. We have been renting but in the current ‘covid’ climate, renting large buildings is likely to be difficult.

 

One suggestion, to allow a quick build, has been to build a large portal frame building, Approx 17m wide by 22m long and 6m high (ridge) with a 6m wide ‘lean to’ running the full length.

 

With regards to the main building, it will be entirely open to use as a sanctuary and my suggestion to overcome the steel frame thermal bridging problem would be to panel the entire inside of the building, flush with plain insulated PIR sandwich panels, walls and ceiling.

One wall will have tall windows in it, one gable will likely have some windows in it, one gable will have very little in the way of windows and one wall will have a ‘lean to’ attached to it.

 

The outside would ideally be panelled in ‘as attractive as possible’ sandwich cladding, possibly with a view to over cladding some of it with timber to improve asthetics.

 

Acoustics will need to be considered, possibly by way of special ceiling panels?

 

With regards to internal asthetics, I understand it could be a fairly clinical looking building but perhaps with decorative timber paneling half way up the wall and regularly spaced fake wooden pillars a warmer look may be achievable - these things could be added later, the main issue being the speed of build presently required.

 

With regards to U/values, SAP calculations and general feasibility, does this idea sound plausible?

 

All input is welcomed and thanks for letting me join the forum

 

Ian

[tonyshouse]

Portal frames could be wood (gluelam) new or s/h steel 

 

I would not use SIPs 

 

are you meaning acoustic performance inside or stopping noise getting out? 

Edited September 13, 2020 by tonyshouse
Sp

[Ferdinand]

1 hour ago, tonyshouse said:

Portal frames could be wood (gluelam) new or s/h steel 

 

I would not use SIPs 

 

are you meaning acoustic performance inside or stopping noise getting out? 

 

The last one will be - 

 

a - Sound projection and echoes etc.

b - Keeping external noise out.

c - Keeping internal noise in if they are the type to have a microphone on the drums.

d - Making people who can't sing sound better.

 

?

 

And welcome to the OP.

 

F

Edited September 13, 2020 by Ferdinand

[Ferdinand]

Reflecting a little, I cannot see why it would not be feasible.

 

But I wonder about rapid timescales being possible - I suspect it will take as long as the COVID vaccine ie perhaps 12 months - and whether other options may be more achievable in a short timescale.

 

eg Exclusive longer term rental rather than eg a school hall on Sunday (or whatever you do now), buy a disused church or hall and renovate etc.

 

There will be numbers of empty buildings soon - eg numbers of gyms are closing permanently including Councils closing the entire service, and some of those are in portal frame or other industrial buildings.

 

Access to these would be via normal property letting companies.

 

Note that you may have much more flexibility following the changes to Use Classes on September 1st. Check with your Council or Consultant on this.

 

Ferdinand 

[why_aye]

Hi thanks for the replies so far.

Regarding portal frames, I'm thinking probably 356x171x54kg ub will be required, 6@ just over 4m centres.

 

My reasoning behind insulated steel panels inside as well as out is speed of fitting, insulating and finish in one easy step.

Why would you advise against them? It's a genuine question because I'm unsure of the best way forward myself.

 

Noise concerns are for internal acoustics/reverb. Solid smooth steel walls will probably give too much reverb for clear speech when the preacher is talking although a little is nice, as you state, to improve singing.

 

It's a rural setting so making a noise that could disturb neighbours isn't a problem.

 

With regards covid, yes, who knows what the landscape will look like in a year's time and there may well be suitable buildings around then, for the last few years there have been none locally. Building quickly is only one option that we're looking into with other options involving longer term builds using timber frame and additional halls, etc as part of the development. 

My investigation at the moment is purely  looking into a fast build that can be extended/added to later.

 

Thanks again

 

Ian

[Ferdinand]

Let me add one further note.

 

I see that the commercial property market is in freefall at present - 14% down on 2019.

 

So if you are one of the few groups with the confidence to buy with a known long term use, it could be a significant opportunity if something comes up. Worth - as you say - a monitoring brief.

All the best. 

 

Ferdinand

 

[Gus Potter]

Hello why-aye

 

With a 17m span you can do a cold rolled steel portal frame, but as your eaves height is 6.0m a colled rolled steel frame is not really feasible to make fly. Much of this is to do with the sway in the frame. So your hot rolled frame is probably the way to go.

 

Yes, you can basically construct an industrial building, over clad the insulated panels on the outside, for aesthetics. You are then free to fit out the space and get the acoustics the way you want. The extra dead load (of the finishes) will add a bit to the frame size though.

 

Just watch the deflection limits - that is partly how much the building will sway , ridge bend by etc. If you are installing "brittle finishes" such as leaded windows etc you may need to reduce the movement so these don't suffer.

 

Normally a standard industrial storage, warehouse type buiding is designed for a column height horizontal movement of height / 100.  So 6.0m tall = 60mm deflection at the eaves.. quite a lot for a leaded window, sensitive (brittle) finishes.

 

I'll post more stuff if you want to follow up.

 

 

 

 

 

[Gone West]

12 hours ago, why_aye said:

All input is welcomed and thanks for letting me join the forum

Welcome to the forum and good luck with the project. We built a timber I-beam portal framed house. It was the second of the type built in Kent, the first being an art studio.

https://conker.cc/projects/passivhaus-artists-studio-canterbury/

 

[why_aye]

Thanks for the info Gus and an interesting link Peter, timber I beams are on the cards if we go for a slower build.

 

With regards the portal frame, I'm probably looking at a 3.5 - 4.5m eaves height with a 6 -6.5m ridge height. Deflection would ideally be kept to a minimum so stiffness would be required - we're building in the Western Isles - it's windy! Lead lined windows are unlikely to be used but standard UPVC at approx 2m tall probably aren't keen on too much movement either.

 

With regards to attaching external timber cladding on top of my insulated sheets, say, horizontal Siberian Larch, what's the best way to get a fixing for my timber battens?

 

And looking again at the insulated interior panelling, can I add the R values of the interior panel to the R values of the exterior panel to get my total value or does the air gap in between, (Approx 300mm in the walls and possibly 500mm in the ceiling), interfere with the calculation?

 

I'm certainly interested in any other information you have that could be useful Gus.

 

Many thanks

 

Ian