SIP house

Spudnik73

Hi,

I am interested in the idea of SIP's (for a new build) and from reading various forums theyseem to offer a lot of advantages namely:

1. built in factory conditions so no issues with poorly fitted insulation etc
2. Smaller cavity & able to get more insulation into a smaller space
3. Air tightness
4. Roof appear to be easier to insulate
5. Faster build

There are others but I see the above as the main ones. For the sake of balance / research I am trying to understand the downsides compared to other construction methods. To this end I would appreciate some input. From my limited understanding I have put down the following:

1. It is more expensive (albeit this is all relative i.e. you get what you pay for.)
2. It limits the changes that you can make on site.
3. The traditional block build allows the heat to be absorbed by the block & released back to the house over a longer length of time i.e. the house will not get too hot or too cold. Conversely because there is no inner block to absorb the heat is it correct to say that a SIP build house is more likely to overheat?

As above this is purely from my limited knowledge & purely for the purposes of understanding fully.

Any input most welcome
Thanks

Poor Uncle Tom

There is a common misconception that a SIPs house is an entire house constructed in-factory thus making it a much better form of construction. This is not the case SIPs is another form of prefabrication. The panels still have to be assembled and joined up on site to produce the final product.

There is an assumption that everything is set up exactly on site precicely in readyness for the panels. This is rarely ever the case as there are tolerences to be worked to. The top of the footings may not be exactly level or the diagonals may not be exactly equal. In cases like this good craftsmen working on site will do a much better job constructing from scratch than any factory made panel could.

Forcedhand

SIP or Structural insulated panels are a good method of construction but like all forms of construction they have +'s and -'s. What I would say on construction methods now is that prefabricated products are better performing than onsite construction. Don't let anyone tell you different!

I'm a Chartered Engineer who has been involved with house construction for a long time. I recently finished a house for a client and we used ICF (Insulated Concrete Formwork). Personally I feel this is the best method around but it does require experienced crew to install and render it. Look for NSAI Agrement certification on all these systems and you will be on the right track. Don't be afraid to ring them either...they're very helpful.

Poor Uncle Tom

Forcedhand wrote: »

SIP or Structural insulated panels are a good method of construction but like all forms of construction they have +'s and -'s. What I would say on construction methods now is that prefabricated products are better performing than onsite construction. Don't let anyone tell you different!

There are a lot of on-site craftsmen out there who would disagree with you very strongly on that.

Forcedhand wrote: »

I'm a Chartered Engineer who has been involved with house construction for a long time. I recently finished a house for a client and we used ICF (Insulated Concrete Formwork). Personally I feel this is the best method around but it does require experienced crew to install and render it.

Any form of construction built to current standards using experienced crews for installation should perform well.

Forcedhand wrote: »

Look for NSAI Agrement certification on all these systems and you will be on the right track. Don't be afraid to ring them either...they're very helpful.

Agreed.

Forcedhand

To be honest I don't disagree with what you said Uncle Tom. The big leap is going from prefabricated products to site construction. In the first instance you are virtually assured of the quality. Traditional built houses rely on a lot of sub contractors to interact seamlessly with each other. In the majority of cases that doesn't happen. I agree with you, if good craftsmen work together they can produce an excellent standard of construction, but how often does that happen?

Poor Uncle Tom

Forcedhand wrote: »

The big leap is going from prefabricated products to site construction. In the first instance you are virtually assured of the quality.

You would assume that this is the case, but it is not a given at all. How many craftsmen or indeed tradesmen work the lines in those assembly plants?
A few years ago I visited one of those plants and took interest in a panel being made, when the panel in question was turned over for work on the other side it was plainly obvious the assembly workers had missed entire rows of fixing screws, the studs had moved and were not secured at all. I presume this very basic error was rectified but, my point is the quality of work was very very poor and in that case I did not accept it.

Forcedhand wrote: »

Traditional built houses rely on a lot of sub contractors to interact seamlessly with each other. In the majority of cases that doesn't happen. I agree with you, if good craftsmen work together they can produce an excellent standard of construction, but how often does that happen?

In my experience it happens quite a lot on a well managed site. It is much harder to get right on direct labour sites, but it is still possible.

It's obvious we won't agree here, but these are just my experiences and my opinion....:)

galwaytt

Poor Uncle Tom wrote: »

There is an assumption that everything is set up exactly on site precicely in readyness for the panels. This is rarely ever the case as there are tolerences to be worked to. The top of the footings may not be exactly level or the diagonals may not be exactly equal. In cases like this good craftsmen working on site will do a much better job constructing from scratch than any factory made panel could.

You see, you've just contradicted yourself there: your saying onsite quality is comparable to factory, yet they can't prepare to level-and-square ? You can't have it both ways: onsite quality always has been, and always will be, subjective, and prone to influence's.

If the builder can't get the basics right, why would you assume they'd get get a fit of conscience later on ??

Building experience in this country has shown that site-built quality has led to a huge diminution of anyone's experience of same.......and of course, add in the mix of price as a variable, then, hey.......if you beat the builder over the head on the price........then the goal posts move......and boards.ie is peppered with experiences of it.

galwaytt

Poor Uncle Tom wrote: »

You would assume that this is the case, but it is not a given at all. How many craftsmen or indeed tradesmen work the lines in those assembly plants?
A few years ago I visited one of those plants and took interest in a panel being made, when the panel in question was turned over for work on the other side it was plainly obvious the assembly workers had missed entire rows of fixing screws, the studs had moved and were not secured at all. I presume this very basic error was rectified but, my point is the quality of work was very very poor and in that case I did not accept it.


In my experience it happens quite a lot on a well managed site. It is much harder to get right on direct labour sites, but it is still possible.

It's obvious we won't agree here, but these are just my experiences and my opinion....:)

The experience you describe is of timber frame, using conventional materials, details and fixings. You were looking at a system manufactured manually, albeit indoors. Put those guys doing that outdoors, as traditionally, and you'd have had the same - and worse - result.

And for one-off houses, you very rarely get a fully managed site, which is what you agree with yourself.

None of that applies to what OP is looking at.

Poor Uncle Tom

galwaytt wrote: »

You see, you've just contradicted yourself there: your saying onsite quality is comparable to factory, yet they can't prepare to level-and-square ? You can't have it both ways: onsite quality always has been, and always will be, subjective, and prone to influence's.

If the builder can't get the basics right, why would you assume they'd get get a fit of conscience later on ??

No, you are mis-understanding what I'm saying....
The point I'm making is that in the very best of circumstances there are tolerences to be worked to, and this includes the level and square of a base. When that is combined with an off-site produced SIP, which is a rigid form. The mating of the two can be more troublesome than any on-site construction.

galwaytt wrote: »

Building experience in this country has shown that site-built quality has led to a huge diminution of anyone's experience of same.......and of course, add in the mix of price as a variable, then, hey.......if you beat the builder over the head on the price........then the goal posts move......and boards.ie is peppered with experiences of it.

Yes, this is the case.

galwaytt wrote: »

The experience you describe is of timber frame, using conventional materials, details and fixings. You were looking at a system manufactured manually, albeit indoors. Put those guys doing that outdoors, as traditionally, and you'd have had the same - and worse - result.

No, the system was a manually produced SIP (the company is no longer going) they made the panels in-house with pumped foam.

galwaytt wrote: »

And for one-off houses, you very rarely get a fully managed site, which is what you agree with yourself.

Yes, it is rare.

galwaytt wrote: »

None of that applies to what OP is looking at.

We have wandered off-topic a bit, having mentioned timber frame, ICF and standard construction where SIPs is the topic, so a note for us all, please post on topic....

To help us out....

galwaytt

Poor Uncle Tom wrote: »

No, you are mis-understanding what I'm saying....
The point I'm making is that in the very best of circumstances there are tolerences to be worked to, and this includes the level and square of a base. When that is combined with an off-site produced SIP, which is a rigid form. The mating of the two can be more troublesome than any on-site construction.

For clarity, and I've ran this by a Mod first, but I do understand: honestly, I do, for the following reasons. I work for the only SIP manufacturer in Ireland <snip>

<snip>

If I take your SIP-to foundation connection issue first: well, for us anyway, it's inherently simple. A CNC machined panel, with a rebate, is fitted over a treated sole plate, which is anchor-bolted to the foundation (of whatever type). I fail to see how that's difficult. <snip>

Ok, away from that a bit. The below is an attempt to, in the case of this subject, if we confine ourselves to SIP-only products, then what are the issues ?

SIP originates in the US, back in the '30's. It was originally designed as a build method to deliver economical mass-housing, to deliver a thermal performance to the ordinary working man/woman/family, compared to existing (no doubt draughty-as-hell) clinker-built houses. It subsequently spread via both Germany (for passive) and Far East (for seismic) reasons, historically. Over time panels have gotten thicker, the skins have changed, and insulation has evolved, as well. Speed of erection on site also made installed-cost lower.

There are several aspects of 'conventional' SIP panels, which we identified, and which we felt, for the Irish and UK market, needed to be improved upon, but, confining myself to your concerns, namely (there are others, but that's for another day):

1. Panel 'assembly'
2. Panel Accuracy of manufacture and resultant quality of assembly on site

The panels you said you saw were manually built with expanding foam, may indeed be problematic, and we don't use injected foam panels for a variety of reasons. It's hygroscopic, for a start. There is no 100% way to ensure no-voids,within, is another. And that confines it's manufacture to panels no more than 1200mm wide....which brings me to your point.....

1
One issue, and which you touched on, is assembling panels to make walls, on site. The ones you see on YouTube etc - we had to get away from that. Making a house partially in the factory, and partially onsite, is a waste of time. Either do one, or the other, so we deigned to remove this task completely. So, we manufacture any single panel, up to 3m a x 15m in size, in one piece. Then there is no joint to make, connect or seal, every 1200mm, as in the ones you saw.

2
Now this, this is a Big Deal. Even in 'traditional' build, quality comes from accuracy, I'm sure you'll agree. Again, to use hand tools to make big panels is not only counter-intuitive, it's slow. So, we have the largest CNC machine there is, with a full 15m x 3m bed, to take the biggest panel. Accuracy is 2mm within 15000mm. It cuts the panel to size, including all door and window opes, Velux and chimney opes (in roof's), and put eave and fascia angles on, as well. It also cuts perfect curves...... There's a reason it cost as much as it did.....

How does that make the point that factory built quality is better than site built ? Well, don't take my word for it: the client's have the 'numbers', to back it up. I've seen airtightness of 0.9m3/hr/m2 - before any plasterboard is fitted, to either walls or ceilings. Attic left open, to include ridge beam and wall plate detail. In a 400sq m house. Or, 0.57 in another house, finished to move-in condition. And here's the key thing: no membranes used. And you can attach something to the wall and you still wont' comprimise the airtightness. There is no 'membrane', to pierce. This quality extends to window and door opes, as well, and confidence of fit. The list goes on and on.

OK, taking all that on board: how does that feed into OP's post ?

er, separate reply for that, methink's........


Edit: posted edited to remove company information

sydthebeat

Poor Uncle Tom

What you describe is a huge leap from the half-baked attempts I witnessed, and not having to join up 1200mm wide panels on site like a giant jig-saw can only make for a much better system. What you describe sounds like the ultimate for anybody considering a SIP build. Thank you for the clarity.

Regarding the OP's concerns, only they can answer whether their concerns have been addressed.

galwaytt

Spudnik73 wrote: »

Hi,

I am interested in the idea of SIP's (for a new build) and from reading various forums theyseem to offer a lot of advantages namely:

1. built in factory conditions so no issues with poorly fitted insulation etc
2. Smaller cavity & able to get more insulation into a smaller space
3. Air tightness
4. Roof appear to be easier to insulate
5. Faster build

1. Yes
2. The insulation used is very dense, so you can get good performance even in modest panel thickness'......
3. Big advantage. It's easy achieve 1.0, and a bit of tlc in finishing etc can see down below 0.6. And without using any membranes. And you can't puncture it by hanging something on the wall.
4. The roof is insulated, as delivered. And airtight. Once fitted (and most are done in 1 - 1.5 days), you have crossed the insulation and airtight 'barrier'.
5. Yes. We put up one on August 2010 in Dublin, and they moved in for Christmas. Again, it's down to planning, detail, and more planning. But, less time on site does lower finished costs - we are all, myself included, paid by the hour. Less hours = less cost.

3 & 4 bring one other un-targetted benefit: sound. Or, the lack of it. By dint of an airtight construction - esp the roof, - they are very, very quiet.

Spudnik73 wrote: »

To this end I would appreciate some input. From my limited understanding I have put down the following:
1. It is more expensive (albeit this is all relative i.e. you get what you pay for.)
2. It limits the changes that you can make on site.
3. The traditional block build allows the heat to be absorbed by the block & released back to the house over a longer length of time i.e. the house will not get too hot or too cold. Conversely because there is no inner block to absorb the heat is it correct to say that a SIP build house is more likely to overheat?

As above this is purely from my limited knowledge & purely for the purposes of understanding fully.

Any input most welcome
Thanks

1. Is it ? I made several contributions to the Prices 2010 thread, so do go through that for yourself. That thread is here, I think you'll find it very useful : http://www.boards.ie/vbulletin/showthread.php?t=2055830286&page=11 Prices anywhere from €70 per sq ft upwards, depending on spec.
2. Not in my book. Like any certified system, the process of getting it certified included 'ease of change'. IMHO, but there again it's bread-and-butter to us, it's easier to change. Either way, it's do-able, without complication. We put up units in Sept 2010, and they've already applied for PP to extend..........ymmv and all that.
3. Ah, you've put your finger on something there. If your building, irrespective of build method is getting that hot, it is suffering from too much solar gain, or, you are overheating it in the first place. Our experience is that because a SIP is much heavier than TF, it is a good medium, on the 'mass' front. Add in UFH or concrete on both floors and you have a good compromise in terms of a nice modulate-able (?) building, that doesn't suffer from the pendulum effect of what you describe. Compared to a cold-roof constructed building, for example it is very stable. Heat, like cold, is a two-way street. If heat can't get out, in winter, it can't get in, in summer, either.......


I'll see if some of the SIP builder's I know are on boards, and ask them to chime in here.

galwaytt

Poor Uncle Tom wrote: »

What you describe is a huge leap from the half-baked attempts I witnessed, and not having to join up 1200mm wide panels on site like a giant jig-saw can only make for a much better system. What you describe sounds like the ultimate for anybody considering a SIP build. Thank you for the clarity.

Regarding the OP's concerns, only they can answer whether their concerns have been addressed.

Hi Tom - tks for your input. As you can imagine, it's something I'm passionate about.

I agree with you - half-baked......half-baked anything is only getting to get people in trouble, and brings a bad reputation. People see our plant and think we're nuts to have spent the €€€ we have on the process. Me, I can't honestly see any other way of doing it. In fact, and no more than a house project, if we were buying that CNC machine again, I'd............buy an even bigger one !

But isn't that just experience ?

But, hey, whether house, factory, PC or laptop - even the dreaded mobile phone - you gotta jump in somewhere, right? :eek:

Juantorena

Spudnik73 wrote: »

Hi,

I am interested in the idea of SIP's (for a new build) and from reading various forums theyseem to offer a lot of advantages namely:

1. built in factory conditions so no issues with poorly fitted insulation etc
2. Smaller cavity & able to get more insulation into a smaller space
3. Air tightness
4. Roof appear to be easier to insulate
5. Faster build

There are others but I see the above as the main ones. For the sake of balance / research I am trying to understand the downsides compared to other construction methods. To this end I would appreciate some input. From my limited understanding I have put down the following:

1. It is more expensive (albeit this is all relative i.e. you get what you pay for.)
2. It limits the changes that you can make on site.
3. The traditional block build allows the heat to be absorbed by the block & released back to the house over a longer length of time i.e. the house will not get too hot or too cold. Conversely because there is no inner block to absorb the heat is it correct to say that a SIP build house is more likely to overheat?

As above this is purely from my limited knowledge & purely for the purposes of understanding fully.

Any input most welcome
Thanks

We've built a SIP house. Been in it for about 15 months. Very happy with the SIP aspect. Approx. 241sqm, two storey - went up in about 8 working days.

What I like:

- It was quick. Essentially as advertised/promised.

- The off-site construction of the 'frame'. I specifically went looking for an off-site system for the house.

- The accuracy that accrued from the above. I remember an internal wall panel being lowered into place between two other in-situ panels. The wonderful 'squeek' as the new panel slid into place...lovely. That sound, to me, tells you the value of the system.

Also your window suppliers/installers will love you. No need for them to come up and measure the opes causing delays - if the SIP supplier is good, the window/door supplier can have great confidence that the size of the ope on the drawing is what it will be in actuality. And as planes are flat and true follow-on trades (plasterers. block-layers, etc.) will appreciate it also and should speed their time to completion.

- Air-tightness. The SIP system in general gives you a great basis upon which to gain very good air tightness. The system we went with allowed us good sized panels so the number of joints were minimised further. Some tape and care with wall penetrations and you're into sub passiv-haus territory regarding air-permeability.

- It's solid. We've had two winters of decent wind levels and not a budge. We've had painters commenting on how little settling or cracking there is at door frames or wall/ceiling junctions.

What I don't like:

- Struggling here but feel I should put down a thing or two for balance. With our suppliers system we had to add insulation - insulated slab on the exterior walls. Badgering would be too strong a word, but I've certainly been 'at' the supplier to increase their insulation to avoid this additional requirement. I think the argument is that there is no particular cost benefit but, philosophically anyway, I think this system deserves as few additional elements as possible. I've actually been at them to start supplying fully completed (internally and externally) panels, following the continental model of almost turnkey solutions....easy for me to suggest that though!

- One thing I would consider more closely is the first floor make-up. We went with joists and a deck upon which we put some acoustic matting and then floorboards. There is some impact-noise transmission, and we're used to it by now. It's not a particular issue but, as I said, I'd consider the options for mitigating against noise transmission more than I had.

Overall, I would certainly go SIP again and recommend it without reservation. Visit the supplier of your system if possible. How good your SIP system is will correlate directly with how good the manufacturer/supplier is. The team that supplied and erected ours were tremendous - knowledgeable, enthusiastic and flexible. Also, if possible, consider the design of your house with the/a system in mind. A particular design - slightly adjusted - can simplify matters with associated cost and time savings depending on the system chosen.

Pm me if you need any further thoughts on this or our supplier.

Poor Uncle Tom

Juantorena wrote:

I'm a big fan of off-site or prefabricated construction for houses. I'm constantly at the local timberframe company who did the frame for my house to do more and more in their factory i.e. attaching external cladding/renders, installing windows, fitting socket/light fittings, internal slabbing...

Juantorena wrote: »

We've built a SIP house. Been in it for about 15 months.

The first quote was from a post you made on the 1st October 2009 and the second was today. In the interest of clarity can you explain which type of house you actually live in.

Juantorena

Poor Uncle Tom wrote: »

The first quote was from a post you made on the 1st October 2009 and the second was today. In the interest of clarity can you explain which type of house you actually live in.

Two storey SIP with external block leaf, render, etc (see attached). Is that what you wanted to know?

For our first run at a build and with budget/knowledge constraints I couldn't really pursue the off-site agenda as much as I really wanted to but the SIP side of things worked out really well and I was very encouraged by it......for the next one .

antiskeptic

Poor Uncle Tom wrote: »

There is an assumption that everything is set up exactly on site precicely in readyness for the panels. This is rarely ever the case as there are tolerences to be worked to. The top of the footings may not be exactly level or the diagonals may not be exactly equal. In cases like this good craftsmen working on site will do a much better job constructing from scratch than any factory made panel could.

Couldn't good craftsmen be relied upon to do something as basic as ensure equal diagonals and level footings? If not, what chance a well built site house?

Poor Uncle Tom

antiskeptic wrote: »

Couldn't good craftsmen be relied upon to do something as basic as ensure equal diagonals and level footings? If not, what chance a well built site house?

I would be expecting that good craftsmen would do a very good job and get the diagonals equal and the footings level.

In practice what this means is that for footings of say 17m x 8.5m there could be a difference in level and square of say 15mm, this would be considered within tolerance. My point was that this is usually not a problem when constructing on-site whereas when something is being precicely constructed in-factory to be brought to the site for fitting it may cause a problem.

Spudnik73

Hi,

Could anybody help explain the difference between a SIP house and what are descriped as "next generation" Timber frame houses?

Many thanks