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Has Tufeco Solved SIPs Biggest Shortfall?


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#1 jayroc2k

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Posted 11 March 2016 - 10:44 AM

This company were at Ecobuild, they are a new player looking for partners. It seems to take on the traditional SIPs and rethought the issues.
  • Proprietary sole plate NOT from wood - No more rotten sole plate
  • Corners as standard
  • Panels can be in any length
  • 150mm width with 0.13 u values
  • The jointing material doubles as a cavity for services
  • Services voids in the panels (no need for battens)
  • Ticks the recycling green button
I will get more info soon as my architect friend is in talks with them as her client is very keen on modern construction methods

Cost? No idea but given how bespoke it is, I suspect it will cost more

http://www.tufeco.com/
Its nice to see someone at least try to rethink building materials since the large company with deep pockets wont take any risk and innovate


I recently saw a large manufacturer boast of a new plasterboard that can take 25gk of weight. In the age of smartphones, they should be ashamed to bring so little (innovation) to the table. Rant over!

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Edited by joiner, 11 March 2016 - 11:28 AM.


#2 Graeme

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Posted 11 March 2016 - 11:01 AM

Missed this completely.

#3 jsharris

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Posted 11 March 2016 - 11:23 AM

What about the main problem though, that of the cold bridge at the sole plate because SIPs need both skins to be sitting on the same foundation?

If a SIPs manufacturer would offer a panel where only 1/3rd of the panel width at the sole plate (the inside 1/3rd) needed to bear on a foundation then that really would be a great innovation. It would make it easy to fit them to a passive slab, with the slab wing insulation abutting the outer 2/3rds of the panel base.

Structurally this isn't that hard to do, it just needs some thin internal webs to increase the shear resistance of the panels so that loads can be transferred to the inner skin. These thin webs wouldn't decrease the overall U value by a significant amount, either.

Edited by jsharris, 11 March 2016 - 11:24 AM.


#4 jayroc2k

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Posted 11 March 2016 - 11:37 AM

That is a question I have put forward to the architect to ask as I did not meet them personally

Fancy inventing one after you complete your house? I am sure it will find lots on fans on the forum. Although, your position as an independent objective member will be compromised by constantly recommending the JSH Sips Passive Panel ^_^

I for one will buy it if it gives me sub 0.13 u-value for a finshed wall width of 200mm, great acoustic properties, no cold bridge and cost no more than a 10% greater than conventional SipS.

#5 jsharris

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Posted 11 March 2016 - 11:56 AM

It's a similar problem to a spar-less aircraft wing design. Years ago I was working with Polish company who had come up with a very neat monocoque wing (not foam cored, as many designs like this are, but twin-skins of composite for the upper and lower wing surfaces) and they had the same problem, how to transfer loads from both skins (top and bottom of the wing) to the wing attachment points on the fuselage.

The answer was some shear webs, supported with foam, fitted between the two skins and connecting to the two wing attachment points (which were carbon fibre lugs).

It would be relatively cheap and simple to design composite Z webs to connect the two skins for an adequate distance up from the base, and then use the foam core to prevent those shear webs from crippling. I doubt it would add much cost to a panel, neither would it have a significant effect on thermal performance. Combined with the Tufeco sole plate, with perhaps some beefing up of the inner 1/3rd, I'm pretty confident that this approach could work well.

There is still the issue of poor acoustic and decrement delay performance, but is the SIPs panel is being used as a structural internal skin with a thin masonry outer skin and a narrow cavity then those issues would be largely addressed.

If the idea was to produce a panel with no need for a masonry outer skin, then a triple skin panel would seem to be a good approach. Use a thin conventional SIPs inner panel (say, 100mm thick) as the structural member, and add an additional outer sandwich that was non-structural but used a higher density (for acoustic reasons) outer insulation layer, ideally from a material like wood fibre that also has a relatively high decrement delay.

#6 1anR

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Posted 11 March 2016 - 12:00 PM

There is a lack of detail on their website, but the suggestion is the core is structural, without timber required to reinforce. Not sure what part the "glass fibre cabling" plays.

Perhaps, with a sufficiently lightweight structure, the 150mm wall panel will be able to sit partially on to the EPS upstand.

Needs an open minded Structural Engineer if they don't already have an off-the-shelf solution.

#7 jsharris

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Posted 11 March 2016 - 01:05 PM

The core is structural in all SIPs panels, but only in the sense that it provides stiffening to the load-bearing outer skins in order to prevent them from crippling. Even thin OSB skins are capable of carrying very high compressive loads applied at the edges, the problem is that as soon as the skin bends out of the plane of the applied load its load bearing capability drops massively. The foam core stops this from happening, but at the moment all the SIPs designs I've seen rely on just using the foam to keep the two load-bearing skins parallel and flat.

To allow the inner skin to take vertical compressive loads applied to the outer skin needs a stronger shear connection than just the foam, but not for the whole height of the panel. At a guess, if proper shear webs were fitted to the lower 1/4 or 1/3 of the panels that would almost certainly be enough to transfer the vertical compressive load on the outer skin to the inner skin and narrower sole plate over the inner part of the base of the panel.

The uncertainty I have with this idea is the ability of OSB to transfer shear loads internally, from the bonded on shear webs through the layers that make up the panel. Mechanical through fixings (perhaps blind rivets to the Z section shear web flanges) would do the job OK, I'm sure, and it may well be that good quality OSB uses a strong enough chip bonding adhesive to make mechanical fixings unnecessary, which would be a big advantage in terms of manufacturing cost..

Edited by jsharris, 11 March 2016 - 01:05 PM.


#8 Graeme

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Posted 11 March 2016 - 07:32 PM

Eh?

#9 jsharris

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Posted 11 March 2016 - 08:10 PM

I've just had a totally off-the-wall idea. The problem with SIPs panels is that both skins transfer vertical compressive loads to the foundation, from the floors and roof above. From a thermal perspective, it would be a lot better if all of these loads were transferred to the inside skin, or perhaps a narrow sole plate attached to the inside skin.

The problem can be simplified a lot, though, as the vertical compressive loads are always in one direction. This means that you could do away with the idea of using Z shear webs to transfer the load from the outer skin, fairly evenly to the inner skin, and instead use tensile members. If the lower edge of the outer skin had a number of very low extension tensile cords fastened to it internally, with those tensile cords running through the insulation to the top of the inner panel, then the major part of the load transfer problem can be resolved, with no appreciable cold bridges. In principle it's no different to pre-tensioned reinforced concrete, where the steel tensile members are tensioned by jacks at the ends of the concrete mould, and remain in tension after the concrete has cured because the concrete shrinks and grips the steels very firmly.

Fairly affordable and very durable low extension tensile materials are around, from polyamides (like "Kevlar") through glass fibre to carbon fibre. The latter is already used in pre-stressed concrete construction, because of the weight saving, but for the modest performance needed to perform this function in a SIPs panel glass fibre tensile cords might well be fine, and relatively cheap and fairly easy to bond to.

Definitely something for the SIPs people to think about, as the advantage of a SIPs panel that doesn't need both skins to be directly supported by the foundation are pretty significant.

#10 curlewhouse

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Posted 20 March 2016 - 05:21 PM

Actually, is this whole issue not a matter of just using something other than timber? Does a soleplate have to be timber? Thinking of something like a dense plastic maybe (thinking initially of the stuff I've seen used to create walkways etc made from recycled plastic - I've used offcuts as a background to a target for zeroing my rifles and it is astoundingly strong).

Edited by curlewhouse, 20 March 2016 - 05:21 PM.


#11 jsharris

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Posted 20 March 2016 - 05:50 PM

The soleplate could be recycled plastic, but that's more thermally conductive than wood, so makes the problem worse.

The solution is to transfer the load from the outer skin to the inner skin, so that the outer skin takes no load at it's base and can sit on the floor wing insulation, in a similar way to a twin-wall or Larsen truss build.

#12 Triassic

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Posted 25 March 2016 - 06:45 PM

Steel frame similar to a BISF house, clad with sips panels, job done!

#13 jsharris

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Posted 25 March 2016 - 06:55 PM

View PostTriassic, on 25 March 2016 - 06:45 PM, said:

Steel frame similar to a BISF house, clad with sips panels, job done!

Funnily enough I saw a commercial building being built in a similar way. They had a steel frame and they attached insulated concrete panels (basically a shiny concrete external skin, over the top of a foam core, with a thicker concrete inner skin that had fastenings cast into it). It looked to be a good system, as they just craned the panels into place, squirted sealant along the edges (which were sort of tonge-and-groove shaped) then tightened up the nuts onto the threaded studs to pull them into place against the steelwork.

#14 hrc

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Posted 08 April 2016 - 09:13 AM

So, a double sips panel - say conventional panel 100mm deep overall, with a second outer core and osb outer - thus: osb inner, 75mm core (bonded) osb (centre) - this makes the load bearing sip - second foam core (bonded) and outer osb - this is non load bearing, does not need high density foam for strength and can be varying thicknesses

Actually, thinking further, if I can get a 100mm sips panel adequate to support a 2 storey + loft build, supported on the outside edge of a passive slab beam (viking type)then a 200mm non structural 'half panel?' on the outside most bases are covered
No cold bridge at floor joint (they sit on structural panel and DON'T project so the outer sails past, 200mm outer is contiguous (could be brick bonded?) with slab insulation - roof joint hmmm more work

Would that work - has it been tried?

#15 jsharris

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Posted 08 April 2016 - 09:25 AM

The outer skin then really becomes redundant. I've said here before that a thin structural SIPs panel, resting on a passive slab ring beam, and then fitted with external wall insulation (preferably something that will add much-needed decrement delay, like wood fibre board) both fixes the sole plate problem and addresses the worst aspect of having all-foam insulation, its short decrement delay time.

The nice thing is that all this stuff is available now, no new manufacturing system needs to be devised. Just build the structural frame from standard 140mm SIPs panels and then fit a decent thickness of wood fibre on the outside. The outer finish could be a breather membrane, narrow cavity and masonry, cement board and slips, mesh and render, or even breather membrane, counter batten and timber clad. All pretty straightforward.

#16 tonyshouse

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Posted 08 April 2016 - 02:37 PM

The sole plate problem is twofold in my view, 1) there is a thermal bridge where condensation will occur, 2) if the sole plate is wood, it is likely to go rotten even if treated and Ben if sitting on a dpc.

If the soleplate is non biodegradable then it will still pick up the condensation and likely breed silver fish etc.


So in answer to the op my answer is no.

#17 hrc

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Posted 08 April 2016 - 03:18 PM

So back to larsen truss! Some sort of combination Larsen Truss bonded/nailed to an internal SIP - Larsen truss filled with cellulose/fibre SIP for structural

Just nail-gun I-beams onto the SIP, add OSB outer and blow fill with cellulose? Be nice if that came to site as a unit. 200mm cellulose + 100mm SIP = 300mm wall plus finishes

QUESTION: How long a decremental delay do we need here in UK?

#18 jsharris

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Posted 08 April 2016 - 03:38 PM

View Posthrc, on 08 April 2016 - 03:18 PM, said:

So back to larsen truss! Some sort of combination Larsen Truss bonded/nailed to an internal SIP - Larsen truss filled with cellulose/fibre SIP for structural

Just nail-gun I-beams onto the SIP, add OSB outer and blow fill with cellulose? Be nice if that came to site as a unit. 200mm cellulose + 100mm SIP = 300mm wall plus finishes

QUESTION: How long a decremental delay do we need here in UK?

Or just a SIP structure with external insulation that is contiguous with the wing insulation around the foundation. Easy to do and not costly.

Decrement delay ideally needs to be longer than the time a surface is exposed to a high differential temperature. 6 to 8 hours is probably OK, but the main thing is really the house thermal time constant - how long does the house take to heat up or cool down when the temperature outside changes by a significant amount?

Our new house has a thermal time constant that's longer than 24 hours, so tends to remain very stable in temperature. Our old house (a late 1980's brick and block bungalow with, with a concrete slab floor, block internal walls, good double glazing, cavity wall insulation and very good loft insulation) had a thermal time constant of a hour or two, so it would cool quickly in cold weather if the heating went off and tended to over-heat quickly in hot weather.