Gaf

Please share, thank you. What was the makeup of your DPC? Cheers for the image. Those thin linear drains look the business. What is your DPC makeup? Is the patio level with the DPC (orange line in OP) or below DPC (pink line in OP)?

Plan from the beginning of build was for our patio to be installed at the same level as our internal floor area. The patio is accessed from our open plan area through a large sliding door (3.5m). Open plan is an L shape and the patio is in the ‘gap’ in the L (if that makes sense) as the plan was to create a sense of the open plan ‘continuing’ out onto the patio. This was communicated to both the architects doing our drawings and the builder prior to starting. The plans have an Aco channel drain specified where the patio and sliding door meet. As the build has progressed and I’ve learned more about regulations, and I’m wondering if the makeup of the wall and DPC will allow us to do as planned with the patio being at floor level. Attached image shows the makeup of the build at the external wall - it's 150mm cavity. The blue is the DPC – there is the DPC membrane running from high on the internal leaf down one block (215mm) to the external leaf, then an additional single piece of DPC running along the external leaf blockwork. We had hoped to have the patio height set at the orange line. Does this DPC makeup allow this, or will we have to keep the patio lower (150mm below DPC) so somewhere approx. at the pink line? The Paving Expert website only seems to include details where the DPC is just one horizontal piece on a single leaf, rather than double leaf house with the sloped DPC.

Contacted one of the MVHR installers locally and he had an interesting take. Said a potential reason the cheaper Galvament unit might be causing the condensation issues is actually, paradoxically, because it's more powerful than the more expensive Faber unit. With airtightness levels in houses, he said a more powerful unit will suck out so much air that the MVHR can't compensate to get enough air into the house, so the fan in the extractor might just start spinning but not actually extracting, leaving the humidity in the air above the hob resulting in the condensation. He also wasn't a fan of the recirculating ones and advised venting externally to remove grease that isn't properly filtered out so that it's not getting up into the MVHR. Said just to crack a window whilst the extractor is on and that's sufficient.

Id be for this but herself wants the cooker hood as a feature in the kitchen. Getting it custom made and ordered already… 😬

So not how our architect spec’d it? 😂

Did not know that! Just searched here and online. If I've understood it, recirculating is for grease filtering while the MVHR generally takes care of the rest? Can I ask what make/model you have? And I can't seem to locate Miele discount outlet - is that in the UK? Meant to mention the extractor has to be a built-in / integrate one as we're getting a timber hood made for it.

Will have an 80-90 cm, likely 5 zone, induction hob with hood extractor. Extraction will be to the outside via the wall the extractor is mounted on. We also have MVHR. Kitchen crew are recommending a specific induction extractor. The 'standard' extractor they do is a Galvamet, but they're recommending a Faber. I compared the specs against each other and almost across the board the 'standard' Galvamet wins out against the 'induction' Faber (attached image comparison of specs). I mentioned this to kitchen crew who said it's the Faber 'Steam Off System' that makes them still recommend the Faber. Said they switched to recommending the Faber because they were getting feedback from customers who had the Galvamet, but when these customers later upgraded to an induction hob, they were getting loads of condensation dripping off the Galvamet. Faber is 500 bucks more than the Galvamet. We're at the last stages of a new build, over budget, so don't want to be unnecessarily spending but also prefer to get this right if it needs it. The Faber has that steam system and is 10cm winder than the Galvamet, but the Galvamet has better fluid dynamics, stronger air flow, and is quieter. Any ideas why the Faber, with poorer specs, may be the better option?

@Andehh It’s a new build. What kind of gap would the slit drain typically be? 50mm?

Planning a porcelain patio and path around house. Always liked the look of stone splash strips between building and paths, but reading up on them it appears they get clogged and weedy, and become another maintenance job. Alternative seems to be grated channel drain, however these look a but commercial and far less aesthetically pleasing. Wondering is there any kind of hybrid method, where maybe the grated part of the channel drain sits maybe an inch below the paving, with stone on top of this grate (rather than deep stones)?

Is there a generally accepted method of slip proofing walk in showers and wet rooms? Reading around throws up different approaches / advice. Most tiles come with an R value, almost exclusively R10 when looking for anti-slip tiles. R11 seem to be reserved for outdoor. However, R10 appears to span a wide range of frictions and can seemingly not actually have robust antislip properties at all (reference website). PTV values seem to be a far better gauge but I haven’t seen this value listed on tiles. I’ve seen posts here about going with smaller tiles for the walk in showers and the grout acts as a grip / anti-slip method. I know walk ins with antislip tiles can be a pain to clean but we’re still interested in doing it for our own. Kids will have a tray in theirs.

There was zero SE input to the original design. We had one lined up, but as they were adamant we didn't need one (we asked more than once), we didn't go ahead - obviously we were very green at the start of this process. From what I can decipher from the way the architect describes what they did, they worked from standard rules. They describe our house as "a simple structure" and a "standard structure". When I asked about the wall with the yellow highlighter and their calculations of the structural stability / capacity to hold what is above it, they just repeat the same line of it being "of standard structure". Not sure they did anything to account for site specific behaviour. The foundation depth, for example, was specified as "Depth of foundations subject to favourable conditions". Unsure whose job it was to define and assess what accounts for 'favourable conditions'. This is the area that's causing me the biggest headache. Architect has been unequivocal that they signed off on the design drawings and want no part in any modifications made on site - and I do agree with them on this, they can't be on the hook for an onsite change that was not run past them. Here's how I'm looking at this (I'm using 'flaw' as a generic term), if the SE reviews the construction drawings / on-site change and: > Flags a structural design flaw on the original construction drawings that needs remediation, then this is on the architect. > Flags a structural flaw in the onsite change by the builder or omission of padstone as specified, then this is on the builder. However, I predict the builder going the route of (a) over engineering and unneccessary to do remediation and/or (b) certifier signed off on it, so it's on the certifier now. > When I flagged the onsite change to certifier, response was the builder "shouldn't have" made the change without telling us but he believes it will be fine based on the builder's "experience". > When I flagged missing padstone to certifier, response was "there should be" one but again should be fine "assuming" block work done well. With a previous issue that arose, certifier said that any issues that crop up down the line then it's on the builder and not on the certifier... Have a Google Drive full of categorised photos to help the SE, hopefully be enough for him to assess the situation. Have got my ducks in a row with the aide memoir alright. Cheers again for the input.

Say an SE looks at this and says it has to be redone / remedial works completed (e.g. pad stone has to go in as per drawings). Does that land squarely on the builder or is there some shared responsibility with the certifier for signing off on the structure as meeting regs? I'm hoping it's purely on the builder because dragging both into it could get messy. The certifier's job is only to inspect on site work to ensure it aligns with BRs, versus also being required to compare on site work against the plans? As in, it wasn't his job to cross reference the plans with the builder's work right to ensure the builder was following the plans? Have an SE lined up to look over the plans and photos this coming week as a first step check. Have it in writing from the Architect that we didn't need a structural engineer, so be very interesting to see what SE thinks. On the phone he said we're probably OK given the architect is a 'proper' one.

@Gus Potter Cheers for taking the time to reply with such detail. Provides further validation that I am justified in getting this properly checked. Im on my phone so apologies if I miss any query or clarification you had asked for. The second photo, yes it is the case that the hollo slabs are resting inside the RSJ and are loading on that single L shaped column. The column is a cavity wall (100mm blocks, 150mm cavity, 100mm blocks). The design specified by the hollo company was for the slabs to be on top of the beams, not inside them. I hate even posting this next bit but how I came to notice this myself is through sheer chance of organising all of my photos from the build. Over time I came to understand some of the building regulations so when I saw this I had a “hmmmm” moment and worst bit is the internal plastering and skimming has been done… (as has the external render) so this can’t be inspected in person without pulling off the plastering. I’m in Ireland and the process is to hire Architect and/or SE who design and spec all elements, and then a Chartered Building Surveyor (CBS), Architect, and/or Engineer are recognised by Building Control (and the bank for the mortgage) as the three professionals qualified to inspect the works in stages. We hired a CBS and I am concerned about the quality of his inspections given he didn’t spot this - when I flagged the missing padstone his first reaction was “there should be” one in place but then rowed back saying he “assumes” the blockwork done is sufficient. And absolutely, as you mentioned, I did not sign anything to take responsibility for any changes. So this will be on the builder. @saveasteading Yea it appears our certifier is a generalist. I hope this doesn’t turn into an argy-bargy between builder and certifier, as it is very likely the certifier has already ‘certified’ the structural build of the house. Has to be looked at regardless. Thank you again.

Yeah a padstone was specified on the drawings and certifier saying it ‘should’ have a padstone but is likely OK. In gathering info at the minute as builder didn’t take it well when a previous deviation from drawings was spotted. Waiting on hollowcore crew to come back on it. From what I can tell there’s no straps used and only a 90mm bearing specified. Its an outside wall yeah, two RSJs used for each opening so they are thermally broken in fairness. Not sure on cavity tray but assume one is there as cavity has been pumped with beads. Cheers. Sums up my thinking. Certifier isn’t exactly backing me up on this point so was really seeking a sense of confirmation that I’m not being unfair in asking for this change to have proper oversight. We’re not confrontational (at least as best we can tell) but the builder didn’t take it well when we flagged all dormer windows weren’t built to the plans, so want to approach this with pure facts and no emotion to reduce fallout. Meant to ask, does “FR” mean fire rated?

Couple queries on this. Forgive the terrible drawing. Along one wall of a new build there are two separate spans (3.4m and 3.2m). Construction drawings and concrete hollow core floor slab design specified: > 3.2m span as RSJ on 450x225 padstones > Concrete floors bearing on top of RSJ > 3.4m span as Steel Lintel First query is whether there should be a padstone at the illuminous yellow spot? The yellow spot is a cavity wall (100 block, 150 cavity, 100block). And if so, whether that one 'middle' block in photo could be the 450x225 specified? Our building certifier's view is 'there should be a padstone there' but it 'should be ok assuming the blockwork was well done'. I personally hate the word 'assuming' for anything structural - but interested in others views on whether I'm being OTT. Above those two spans (and that illuminous yellow wall) is the majority of the second floor wall of the house. Second query is just on whether there's any issue with the hollow core floor slabs having been placed inside the webbing of the RSJ and on top as specified. I'm waiting on a call back from the hollow core crew who specified the bearing as being on top. Certifier says it's normal to put them into the webbing - nothing to worry about. Third query relates to the builder's decision to change the make up of the specified steel lintel over the 3.4m span to RSJ. Construction drawings specified a thermally broken steel lintel. Our building certifier said the builder didn't run the change to RSJ past him and it wasn't mentioned to us. Certifier's view is the 'builder shouldn't have made that change without telling us' but that it's nothing to worry about, no structural concerns in his opinion, and the builder used his 'experience' to make that decision i.e. no SE has had eyes on the change. This entire wall is 8.7m long and two storey high. Length wise it's made up of 1.7m block wall - 3.4m span - 250mm cavity block wall - 3.2m span - 250mm cavity block wall. Conscious of how much of this entire side of the house is held up at this location.

Genius. Wouldn’t have thought of that. Just to make sure I’m understanding it. Is the water from your DHW tank pumped through a separate ufh pipe connection to your bathrooms? Do you find the floors heat up quickly enough since it only kicks in to heat the floors when you’re showering?

Do you have them running on their own pipe separately from the UFH?

You’ve never needed the UFH upstairs? Seems to be very common not to put it in alright.

Just realised my question isn’t too bright… sure the room temperatures will be ~21 so how would a towel rail at 22 do anything. It would have to be electric

Read a good few posts on this. Original plan was electric towel rails but electrician put us off (can't recall why) and suggested we have the UFH feed into towel rads. More reading suggests this isn't necessarily the best as UFH flow temp in our house is estimated at ~22 degrees. Gonna test 22 degrees myself with my hand but curious if 22 would be now where near sufficient for a towel rail max temp?

External wall makeup (outside to inside): - Parex Monorex Render - 100mm block - 150mm cavity bead insulation - 100mm block - ~5mm Parge coat (sand cement) - 37.5mm IWI (25mm PIR) with integrated “vapour control layer” - Skim finish IWI was being installed dot dab but they weren’t sealing the perimeters or fixings. Builder said they could pin them all with mushroom fixings instead for tight to wall sealing. I spoke with Kingspan and Siniat technical departments on this - named the boards being used as having VCL and both said no issues at all pinning the boards tight with mushroom fixings. Thought came to mind about vapour control on this wall buildup with multiple mushroom fixings piercing the VCL in the plasterboard. All fixings are metal - I understand these can create thermal bridges but we’re preferring over plastic for fire safety (all caps being coated to avoid rust). Given the 150mm CWI, that effectively places the parge coat and IWI on the warm side, so regardless of piercings in IWI VCL, I’m hoping this isn’t a recipe for condensation and mould down the line.

Ah. Hmmm. So when the system is being first setup, one way to attempt to mitigate this is getting the balance right when first setting up the system. This probably takes a bit of time tweaking the water flow from the manifold? Sorry, I know I've a tonne of questions.

Ah that's really clever. Had not considered this as a possibility. OK so if we have thermostats that are allowed to open / close loops, and call for heat, we risk a room with say high solar gain heating up to a point the thermostat says "no need for heat in this room anymore" and closes the loop. This could lead to less water flowing, with the heat pump possibly cycling on and off, rather than just running along as it is best.

With micro zoning, I was trying to differentiate between how it appears 'unzoned' seems to generally refer to having one floor of the house as a single zone, so I was trying to figure out 'unzoned' versus 'zoned' versus 'mircozoned'. For a novice the use of similar terms for different things is tricky. If I'm reading you right, you have one zone but multiple loops? And you've had your loops installed in a manner that there is 'less' / ' more' UFH pipe work (for each loop) in some rooms, and this is how you have managed to balance different room temperatures? So in one room there may be a lot of pipe work, so a lot of heated water gets to this room in the pipes, whereas another room has less pipework, so less heated water gets to this room, all while the same amount of water is flowing? Terminology-wise, what do you mean by a "buffer"? Is that a buffer tank? For us, ours has mostly been installed on ground floor, with thermostats on each room. However, whilst these appear to be unwarranted, my plan was to have all rooms at the same temperature, effectively creating an 'unzoned' ground floor.

Ah. We have no rads…