MJNewton

Not wishing to hijack the OP's thread but what about large open plan (shared) spaces e.g. kitchen-diner-lounge type layouts? Or would that be more of a case where one might just have to compromise, depending on the layout (e.g. if the kitchen is closest to the door)?

The screeder came on Saturday to dig the old screed up; I helped him with it partly as I did feel sorry for him having to rip out his own work but also didn't want to let him loose with a breaker (my breaker I hasten to add!) so near to the new doors without supervision! He came again today and put the new screed down: It's a modified sand and cement mixture so will be fast(er) drying and therefore less prone to issues. Time will tell!

Good tips; thanks.

Thanks for that I do prefer the sound of a bonded floor (no pun intended), and whilst the floor is flat there are some areas of slight unevenness so an soft adhesive bed would be ideal.

From what I've read about Truscreed it seems pretty much impervious to curling with it being bonded and fast drying. It is available with fibres but I am not sure if that's the mix he'll be using (the original screed had them).

Okay, glue-down it is! Would an underlay still be required (noting this will be engineered wood if it makes any difference)? I thought perhaps the adhesive does away with the need for an underlay but I see that specific-for-glue underlays are available.

We haven't picked the flooring yet (some way off that to be honest) however I was expecting it to be around 15-18mm. To be honest I'm not sure what drove my down the floating road... I think I may have been thinking it might be beneficial should I ever need to re-lay some of it (e.g. due to damage)? Noise it arguably a more day-to-day issue though and so perhaps I should re-think that.

Does anyone have any knowledge/experience of underlay for floating engineered wood flooring on a concrete base? From some cursory reading it seems that there are varying thicknesses, tog ratings, sound insulation etc and of course price. My initial thoughts are that a decent thickness and tog rating could be beneficial on a ground floor, however I wondered if this would lead to sponginess/springiness underfoot? Perhaps it's a good thing having some 'give' and it may make it a bit quieter to walk on? Speaking of sound, I am assuming the 'sound deadening' underlays are more to minimise transmission of noise *through* the underlay (to rooms below) and not for reducing floor-related noise within the room itself?

An update following the screeder's visit today: I was all prepared for the inevitable 'it'll be fine' and 'must be something I've done' lines but I needn't have been so cynical as there was none of that! The screeder was really disappointed by what has happened and whilst he couldn't say exactly what the issue was (possibly a slightly-too-wet mixture causing it to shrink more than it would otherwise done) he is keen to get it sorted. He came up with two options: 1) Cut out the bad corners and re-screed them, or 2) remove the whole lot and redo it. We agreed that option 2 was probably better even if it is more work, although I did offer to assist with the removal. He also said he would use Tarmac's 'Truscreed' screed this time which has an admixture requiring less water and therefore giving faster drying times. This will not only avoid delaying my project (it will actually be dry before the original would've done) but the shorter drying time also means less chance of drying-related issues. Truscreed is also suitable for bonding even at 80mm thickness and so that's what he'll do this time. So, whilst I am very disappointed that we have this problem I can't fault the screeder's response and so this is a net positive in my book. If there was any negative it's that I discovered I paid more than I could've done given he was actually a subby to the firm I contracted and they added on a decent margin. Still, at least they quoted (and delivered) whereas most companies didn't even return my calls!

With the screeder coming on Thursday and me having taken measurements today I'll see what it's like then and which direction, if any, it's gone in!

It was bang on when first laid, and indeed for a weeks afterwards as I kept an eye on it as I had read a lot about different screed failures and was mindful how critical my joins were. It's only since I've taken my eye off it has it moved! I think that even with some sort of expansion joint the curling would still have happened with the same consequences re heights. If anything, reinforcement between the two floors would have better to prevent differential movement. I've been reading more about it and it seems it may even curl back down (slightly, if not fully) as the lower levels dry out, and it could of course get worse still before it gets better so it may be a little early to be making good with levelling compound. This sound hopefuly from BS8204-1 (Screeds, bases and floorings): I obviously want this reversal to happen (we are a long way off covering it) and so will try covering it as I'd read elsewhere. The screeder is not coming until Thursday and so I've got five days to see if any reversal occurs.

It was laid straight on to the concrete slab beneath, albeit with a DPM between the two (as I beleive is fairly common for this type of screed). The join with the lounge floor has some differences in height but this is likely as much to do with the less-than-perfectly-flat existing lounge floor than anything else. Also, at this end the screen depth was more towards 80mm compared to the 60mm or so at the door end and hence is likely a bit stronger.

I am currently building an extension to increase the size of our lounge and have had tradesmen in to do some aspects of job, which included laying an unbonded 60-80mm fibre-reinforced sand and cement screed to finish flush with the existing lounge floor and a concrete threshold running along a set of doors. Here it is: This was done 6 weeks ago and, as per the screeder's instructions, it was left covered with a polythene sheet for a week to help the initial cure and has been left uncovered since at a room temperature of ~16c - not for any particular reason; although I was mindful that the slower it dries the less issues I would likely have. Unfortunately I noticed today that the slab has risen ~7mm along the join with the door threshold as seen here: (The black sheet on the right is the separating barrier between the screed and the concrete slab underneath but it is very thin and so not affecting the measurement like it might appear to be doing). From what I have read, unbonded screeds can be prone to curling as a result of the top surface drying out quicker than the bottom and so whilst it might not be that surprisng that this has happened I am keen to get it sorted. It's not just the height differential that concerns me (some self-levelling compound to bring the lower levels up could likely sort that) but more the fact that you can feel movement in screed if you jump up and down there. There's no cracking (yet!) but it is definitely flexing. The screeder is coming out on Thursday to have a look but I would welcome anyone's thought on what options I have, noting that I'll be covering it with a 15-18mm engineering wood floor eventually. Thinking aloud I thought I/we could: 1. Do nothing - not really a viable option (for me at least!) as it'll obviously compromise the final floor covering 2. Bring the threshold height up with some form of self-levelling compound - this still leaves a poorly supported screed in the affected areas which may cause issues a later date (although I imagine engineered wood flooring itself provides some strength?) 3. Drill holes and force some sort of resin in/under the screed and then bring the threshold height as required - don't know anything about this as a technique; it just sounds like a possibility to me. 4. Try and get the screed to settle back down by jumping on it and fill what I assume would be a resulting crack 5. Cut and remove/replace the screed as required I did read that sometimes the curl can be reversed by putting a polythene sheet back over the affected areas for a week to move the residual water balance. I am surprised that this could work but I've seen a few mentions of it in what appear reputable places. Does anyone know anything more about this? I suppose it's got to be worth a try before Thursday just to see if anything changes. Grateful for any thoughts!

Thanks everyone; a unanimous opinion really helps. I've just caught a glimpse of one of the panels in low light and the white 'paint' mark *really* stands out, even at a distance. Anyone any idea what white substance is used in the manufacturing process? The supplier has just got in touch to say they've sent my email and photos off to the manufacturer so we'll see what they have to say. Mr Punter, its not low iron glass. The blue tint is a coating intended to help reduce glare. TuffX's version is called Ambi Blue. I don't know how it's applied but finger's crossed it is an accurately repeatable process.

I have just taken delivery of a 2.5m x 1.5m Korniche roof lantern and whilst I am very pleased with the frame two of the 'TuffX Ambience' glazing panels have some defects on the inside (i.e. within the cavity) as per photos below. One has a 2mm diameter white mark (almost looks like a spec of paint!) on the glass and white powder on the black edge spacers: Another panel has a ~18mm mark (scratch/abrasion?) on the glass: There may be other, smaller, marks on this one also. Would you accept these panels? I have read the GGF Code of Good Practice on the subject of what is acceptable and it is, perhaps understandably and unavoidably, still somewhat subjective. I am mindful though that this roof lantern is intended to be something of a focal point, not just a means to let light in or us to see out, and so visual imperfections may have more of an impact than they would in a window. Furthermore, it will always be at most around 1-1.5m away in view and so an 'only visible when close up' consideration isn't all that relevent. I have sent some photos to the supplier and so will see what they say but I thought I'd share my worries with the panel for comment. With this glass having a slightly blue tint do you think I could end up in worse situation if I insist on replacements given the potential for differences in shading between batches?

The kitchen being a 'special location' is no longer the case - it was removed a few years ago.

Thanks both. I must keep reminding myself that any negativity on my part is merely the result of observations of what's in front of me and if its wrong it needs calling out. Whilst it is wrong to expect professionals not to make mistakes (we are all human), it is only reasonable to expect them to be rectified once identified.

Bit more of an update... The BCO came out and listened to my concerns about the falls. He wasn't half as hard-lined about it as I thought he was going to be but did say he'd go back and speak with his manager about the situation, and he also said we should wait for the membrane manufacturer's opinion on the quality of the application as it could make the fall situation a moot point... And it looks like it has... The manufacturer phoned me today and said the application of their product in this instance was 'shocking' with numerous issues including pinholing of the surface, the wrong joint tape being used, uneven thickness etc. They are going to put everything in writing on Monday. I told the builder and he told the roofer. Both seem to be fuming and will be visiting site next week with the local supplier/trainer of the product used as the roofer seems adamant he hasn't done anything wrong. Not particularly looking forward to that one as I don't like criticising people's work, particularly in front of others, but I will have to at least point out all the bits that I sent photos of to the manufacturer so that they can all see what they've seen. So, in my view, the fall issue has been overtaken by the membrane installation issue now. If the manufacturer isn't willing to provide a guarantee against failure in this instance then nobody else is in a position to do so either so that's my option 1 (leave as-is) gone. If the report says that water may have already got through then I think the line I'll be taking is that I want the whole roof structure stripping back to the joists (option 2) as if the roof structure was built well enough to keep moisture out then if any water does get in their it's going to stay in there and I'm not at all happy about that. With the roof stripped back we can of course then put the proper firring strips in before building back up. I've been really enjoying the building of the extension so far but this whole roof business has really left a sour taste which is a real shame for all concerned. Hopefully one day I'll look back and laugh about it.

Ah okay! Not got one of them; sounds fun though.

Shot fire? Overboarding is a challenge in this house as the ceilings are suspending on resilient bars (for noise reduction) and finding them with screws without finding the joists can be tricky!

I'm not overly worried; as Nick said if there's a beam-twisting fire going on I'll be out of there in a flash and chances are it's a complete rebuild anyway from that point.

The beams are recessed and contained entirely within the ceiling void. It was this from the Application Instructions that made me think otherwise:

It's already primered so I think it can go straight on. It's not really a cost issue; more what was going to be easiest in this particular situation.

If 4.2m is my length I've got roughly 0.7m width of exposed surfaces so that's ~3m². A litre of Envirograf EP/FS/INT should cover 10m². All said and done though I think I'm leaning more towards the boarding now if I can get it sorted without too much of a headache. It feels a bit more predictable in its performance, as is often the case with more conventional methods.

For the amount I'd need it'd only be £20.