Hangar concrete specs

[RFguy]

How much is price in your neck of the woods for 32 MPa concrete  /cuM with a batching plant local ?

[RFguy]

I am seeing around $300/cuM for 32MPa in country NSW.

[Ian]

On 10/12/2022 at 5:06 PM, facthunter said:

Expansion is a problem with single sheen and curved.  Nev

Is would be simpler with multiple sheets not a single sheet, using three sheets, ie 2 sides and a top sheet over the crest gives sufficient expansion on GA hangar sizes. On a larger project you'd be putting in expansion joints when you exceed 23m spans.

On 10/12/2022 at 5:21 PM, facthunter said:

The continuous sheet wants to lift of the structure when it gets hot in the sun.  Nev

Even with a single sheet.On a 20m span you get about 12mm of expansion with a 50C temperature change which is reasonable. So about 6mm on each side which should be manageable using standard attachments and tolerances.

 

[facthunter]

Overlaps without enough fall are risky from the leaking point of view in strong winds. Condensation is also inconvenient when it stains your costly paint job. or rusts valuable engine and electrical parts. A hangar HAS to be quite well done including wind related strength and fire. Nev

[Kyle Communications]

I think its a similar price in Childers near my farm too

Will let you know soon  I have to get a truck in

 

[Ian]

1 hour ago, facthunter said:

Overlaps without enough fall are risky from the leaking point of view in strong winds. Condensation is also inconvenient when it stains your costly paint job. or rusts valuable engine and electrical parts. A hangar HAS to be quite well done including wind related strength and fire. Nev

Yes, you're right, however an arch type hangar, width 20m with 3x8m sheets spanning the roof, with glulam beams ~400mm deep providing support, and cross bracing using standard strapping would meet Australian standards in terms of strength and wind loads. Cyclonic wind loads or public shelter requirements might need thicker sheeting or plate attachments but that's out of scope for my needs.

The centre section is spanned by a single sheet and the fall at the point of the join is well beyond minimal fall to ensure that leaks don't occur. Condensation is reduced by a vapour barrier like sarking and is the recommended way to mitigate this, birds in hangars seem to be more problematic for paintwork in practice.

 

Solid timber maintains its strength for longer under high heat loads, however it does burn of course. The main risk from a durability perspective is probably termites and from a construction perspective finding someone willing to build the arches cost effectively to spec.

 

An arch is more efficient in terms of steel used than a box and you can use dish drains rather than guttering so it's a bit of swings and roundabouts.

 

You can go pretty large with simple wooden arch frames.

https://internationalforestindustries.com/2019/04/17/nz-massive-new-hangar-wood/

Edited December 12, 2022 by Ian
typo

[Bruce Tuncks]

Wow that arch hangar is really impressive. There would be a span where the arch became economical compared with galv.

I reckon though that a shed-type hangar of about 12m span would be cheapest when the doors etc were all added in.

At Gawler, many of us owned tee hangars, but these were replaced with standard sheds by the contractor. My guess is that the labor component was higher for tee hangars. 

DOORS....  Sliders are difficult to get to work easily and reliably, I prefer bi-fold swinging doors but be careful

[Ian]

1 hour ago, Bruce Tuncks said:

I reckon though that a shed-type hangar of about 12m span would be cheapest when the doors etc were all added in.

Yes you're probably right. Curved beams in wood are cheaps than steel generally, I just like the whole ww2 vintage feeling of the arched hangars. 

Sliding doors start off nice and over the years become more difficult and you arms need to become stronger.

 

[RFguy]

as expected, slab cost turnkey, with >6" of coarse  fill + buildup, 6" slab n piers, thick at edges etc etc etc etc  $120/sqM finished. 

[Ian]

The stabilised earth  floor is starting to look attractive.

[facthunter]

You can Oil it or hot mix it. Keep water from flowing below it, Compact it well and maybe mix some extra things with it. Easy to  repair. Nev

[skippydiesel]

28 minutes ago, Ian said:

The stabilised earth  floor is starting to look attractive.

Just had my new Sonex on a compacted earth floor - I am sure its cost effective but it smelly, dusty and if there was oil involved in the mix, sticky.

[skippydiesel]

May be I missed it but has anyone mentioned the WW2 "Quonset Hut" - It was probably the Yanks that developed them, as prefabricated structures, easy to build transport and amazingly resistant to even the worst weather. Came in all sizes. 

[onetrack]

Time to gather up some termite mound dirt! It makes the best floor ever, when made into a slurry, and compacted! Dust free and hard! Mind you, you'll need to crush up few hundred mounds!

 

Edited December 13, 2022 by onetrack

[Bruce Tuncks]

RF guy, I reckon $120/sqm is about right but too much. That's $12,000 for a ten by ten m slab. The first savings would be thinner concrete ( 3") with more sub-base compaction.

The posts about earth flooring are interesting, You will need to consider if you are going to do engine work in the hangar.

 

[RFguy]

Bruce
that's with all the pier foundations, and reo, heavy base material buildup to get the slab out of the ground a bit, turnkeyed. yeah its a chunk of cash. But's its one thing I dont have alot of experience with some I might watch how its all done. STructure assembly- well that is a mechano set. 

ON FIRE AND HANGARE DUAL USAGE AND INSURANCE
I've still got a bit of homework to do on fire an insurance. See, the intention is to combine my electronic workshop in, in a sealed off sub rooms and mezzanine. But thinking about it,  I'm pretty sure that the insurance company will hesitate to ensure with hundreds of litres of fuel sitting out there in tanks.
I  have a few options. note- all options are 18m wide .  I'll need to ask the local avaiation maint facility what the insurance position is. 
1) build two sheds. 18x14 + 18x12 #1 airplanes only,  #2 large workshop. with separate walls (or common if concrete)  Building two is about 1.5x the cost of building 1 big one.
2) build one 18x 24, and put a fire wall down the middle and fire suppression system (2000 litres of water in tanks ready to go with roof sprinklers) ..  in the event of a fire, which would burn hot and fast, I have to consider what happens to the roof supporting columns over the structure.

3) Build 18x18, - planes live in the front 12m, and operate my temporary workshop in the rear 6m   And remove fuel the aircraft wwhen stored inside until I build building #2 behind.  Then later build 18 x 8 behind it.   removing fuel each time is a major PITA into a outside approval tank/container , but doable.

 

I do have limited cash, and it could mean I need to do things is more stages. 
These are not for commercial airplane  workshops, I dont need depth to have planes piled up between jobs. The game is to squeeze a Sav + a 182.  (its likely the 230 will go in the near term and I'll have a Sav and a 182  / or Mooney etc) .

 

The concrete certainly wins if there is a common wall.  If there is an explosion, what let's go ? the steel gable roofing sheets ? the front hangar doors?

there are quite a few lightweight fire resistant facade materials 
https://www.fireproofcladdingfacades.com.au/ultramgo-wall-overview.html, but I do have some research to do on understanding capabilities and requirements

Edited December 13, 2022 by RFguy

[onetrack]

Two structures will need at least 5M spacing between them to prevent a fire from one, reaching the other. Strong winds fan flames, and the winds are invariably blowing in the wrong direction.

The thoughts around fire are good to have. Fires start all too easily. Sources of ignition must be recognised, and even arson connected to theft must be taken into account.

Doors will let go first in the case of explosion. A full height firewall will prevent fire ingress into areas that you want to protect. Remember that smoke and water damage is also part and parcel of fire results.

Fire alarms that detect smoke are good to have. If you get to a fire early, damage can be limited. Keep a number of decent fire extinguishers located in easy to access positions, and make yourself and others familiar with how to operate them.

[danny_galaga]

I'll have to check the specs of the manky old carpets that cover the dirt in the hangar I'm in 😄