Mulberry View

Again, Pasquill didn't design it this way, so what ought I have done? Added it? The scheme was designed on Mitek software by the way. I have full 3D's of them if you want a look!

Conversely, my own surveyed measurements were so tight, nothing in my first floor scheme had to be adjusted. Everything dropped straight in. The roof scheme is largely the same, but my 'squint' cuts had to be made on site by me to ensure sufficient bearing. All cuts were made from the verified trimmable portions of the joists. I just don't know what else I could have done!

It's one thing making recommendations, but you went in fairly heavy-handed and caused me sleepless nights without having the full picture. This image that I posted on Page 3... Is directly from Pasquill's design, which has been agreed with my engineer. The whole of the first floor is in the same principle. Are Pasquill's design engineers not capable of engineering this? But just to be sure, my SE spec'd 195x47 for the Ledgers for the first-floor joists after examining the scheme before it was signed off. The same principle was used for the roof ledgers, so they are probably overkill. If I deviate from their designed scheme, will they underwrite it? If you were the engineer here, would you underwrite it if it hadn't been installed as designed? I think you know the answer to that, so for that reason, I have installed it to the absolute letter. So what could I have done differently? Questioned Pasquill? Questioned my SE? I am a ruthless worrier, so I have done both and both times the same verdict was returned. Fun Fact - My First Floor has been engineered using predominantly top-chord hung Posis and cleared for the 750kg loading needed for a large bath upstairs, along with a 2.3m high 2.6m wide 3-sided triple-glazed Oriel Window. I can't imagine what that will weigh.

Any suggestions on what to use to make an airtight seal between wall plate and ply? Or is a bead of sealant between the two enough?

Sorry I didn't thank you for posting this. It's what I'll use.

Without wanting to get all mushy over some guttering, that looks delightful.

I mean, I'm literally talking about 3 linear metres or so of guttering here, its not going to break the bank! I just want to have it detailed better than a plastic soffit board behind it etc.

Pasquill designed the scheme and it was cross checked by my SE. 45mm bearing is all that was needed. I am almost resigned to gutters now, they are only short lengths and I'd like to beautify them as much as possible ideally with Zinc details/flashing etc. I just need to understand from the Zinc contractor whether he needs to come before the single-ply membrane goes on because there is a 'for and against' regarding who comes first.

I have fixed the Posis that top chord hang down to the Ledger with pairs of good quality 5x85 screws. The short bottom chord is as designed.

I greatly appreciate all replies on here, well except for @Dave Jones. Firstly, I am the 'builder'. Nothing has been butchered, I take great offence at that. I have also not improvised. The whole scheme is installed to the absolute letter of the structural design and this mindset is what has led to this post. I am concerned about deviating 'off plan', but I don't think the Architects plan has been thought through. The Ledgers are mounted to the ICF with pairs of M16 bolts at 800 centres and with concrete pads directly through to the back of the timber as seen here. This was agreed with my engineer. The Posi scheme was designed by Pasquill and meets <10mm deflection limits. I have a designer there who has been exceptional and we have carefully examined every detail as I wanted to understand it all. I'd be keen to hear what you think has been butchered as I take great pride in my work and strive for perfection. I know you're a great contributor here and take all (most) advice on board with great appreciation, but I'd love to see/hear some substance to your suggestions as you've added another layer of worry at a time when I could do without it (unless its justified of course). @ETC and I are chatting in DM's. I am beyond grateful for his input and he knows that.

Yes I know. We might end up with one on a little garden building just as a feature to keep 'er indoors happy.

SWMBO would KILL for a rain chain. Honestly.

I'm starting to think the same way. It's a short section (around 1200mm max), we could have a nice gutter and downpipe on that side. That wouldn't bother me, I guess I just need to understand how the edge would be detailed and if that would look OK.

I'm starting to think this roof may have to be open and into a short gutter. I'm fast running out of time.

Would be lovely to gain that much space back, but what about the insulation under the VCL? Everyone seems to say that's a no no.

Indeedy, and the fact that I am facing this problem doesn't write the whole design off. As someone who is not a 'tradie', this has been an ambitious build and far harder than a straight-forward square/rectangle building would have been, but that doesn't take away from how pleased we are with how it is turning out.

Dave, again, please stop posting here. It's not helpful. The fact that you think those 2 roofs should be joined shows that you do not have a good idea of how the design works and therefore should not try to give advice.

Am I right in saying that a hopper could only be used with a parapet wall in this scenario?

@ETC My sketch is getting a bit ugly now I'm tippex'ing and scrawling, but what would be the effect of reducing the insulation on the flat roof to, say 150 or 175mm when the rest of the house is at 200mm? If I could do something like below, with 100mm base layer of PIR forming the bottom of the gutter and the Parapet be 150mm above this, I'd be in the ballpark of 275mm total height, 75mm under the window at the worst point. Keep in mind this is ICF, in my original sketch I thought it was sufficient to have made the PIR lap over the EPS inner skin of the ICF.

No I hadn't. I think I can accommodate insulation in the Posi area, but worry about the hybrid roof thing as this will be under the VCL. I agree on the box gutter shape. I'll have a measure up today and see what I think I can do with having fully vertical sides. I'm just trying to get as much PIR as possible over the wall-roof junction as I imagine that's where potential bridging issues can arise?

Crikey, that does sound like a similar situation. We haven't ordered the windows yet, but I'm reluctant to push the sill level up as it'll be my Grand-Daughters bedroom. I wanted her to have a low sill (I already had to raise it from 800mm to 900mm off the floor). If I have to I will, but it's a last resort. Is the Alwitra VSK the gold standard for this type of coating?

Yes, OSB is what most seem to suggest as Plywood can apparently delaminate under a fully adhered membrane. I agree, the way I've drawn it is off, but I'm trying to figure if the general principle works. Mainly in terms of the parapet wall height in relation to the insulation depth.

@Dave Jones With respect Dave, can you ease up on tearing holes in our design. I hate our Architect with a passion, but we're generally very happy with the overall design. I could do without anything else to feel negative about right now.

Here's a rough idea of what I propose. If this could work, it would be the preferable option. Horizontal Parapet wall on the green lines.... Integral gulleys on the thick red lines. Outlet into the denoted hopper. Flat roof falling in the direction of the red arrows... Very roughly this. The scale is off and the measurements are for guidance. We had planned to fit 200mm PIR into the main roof, so I guess we need to do the same in the flat roof area? 120mm meets our declared as-designed SAP, but we want to do much better than that. I've shown the PIR cut at an angle so as to keep the 200mm thickness as far as possible, but oversailing onto the EPS inner skin of the Nudura. Of course I realise I'd have to place firrings under the Plywood for the fall. Keep in mind there is an outer unifying 50mm skin of EPS to go on in addition to that drawn, this will cover the external timbers. What width should the Parapet be? From the centreline of the Nudura outwards it would be roughly 200mm without needing that inward overhang and might allow the PIR to oversail a bit more. We would run the EPDM up the adjoining walls of the two-storey building. If the Parapet can be kept to 250mm maximum as denoted, it would leave 80-100mm underneath the structural opening of the window. Also, depending on what height the Parapet would need to be in relation to the insulation and gutter depth, it might not even need to be as funky as I've drawn it. @ETC - I would be very happy to pay your rates to do a proper detail drawing if you think a version of this/your idea could work. Any good?

That's an awesome help. You wouldn't believe this but the penny dropped for me earlier this evening with a similar solution. What you've done pretty much nails it, but I'll try and draw what I have in my mind and perhaps run that by you? I'm so grateful for you taking the time with the above.