Gone West Posted January 21, 2018 Share Posted January 21, 2018 6 hours ago, ProDave said: I only see the joist sizes not the layout plan? The joist sizes are in the second PDF file and the layout in the first PDF file. Link to comment Share on other sites More sharing options...
readiescards Posted January 22, 2018 Author Share Posted January 22, 2018 21 hours ago, Oz07 said: Is the sag static or moving depending on load? If it's a permanent sag could you not lift the underlay and carpet and latex floor? The sag I measured is static The bounce I get when someone walks around is too small to measure with my gear Link to comment Share on other sites More sharing options...
ProDave Posted January 22, 2018 Share Posted January 22, 2018 16 hours ago, PeterStarck said: The joist sizes are in the second PDF file and the layout in the first PDF file. My bad. Because the links are on the same line without even a space berween them I thought there was just 1 link. I don't see the chimney in the joist layout, just a big opening that I assume is the stairwell. I am wondering if the "problem" is just the size of the joists. The smallest they could get away with that just about meet the requirements for sag? and perhaps my own joists (similar span and no walls above) have simply been over engineered to give a better result? Link to comment Share on other sites More sharing options...
Gone West Posted January 22, 2018 Share Posted January 22, 2018 8 hours ago, ProDave said: I don't see the chimney in the joist layout, just a big opening that I assume is the stairwell. We don't have a chimney and yes the opening is for the stairwell. It does seem, for my case, that it is well (over?) engineered but it is rock solid. I can't understand why they would use only one metal strap in some places and narrow cords, but then I'm not a SE. Link to comment Share on other sites More sharing options...
Alexphd1 Posted January 23, 2018 Share Posted January 23, 2018 (edited) I was getting slightly worried reading this thread as we are installing our wolf posi joist this week. Our joist are designed to hang by top chord on a 47mm wide batten one side and 100mm other side. Span is 5.6m WS250 joist that is 147mm wide @ 400 centres. No steel joist hangers. We have tightly packed the bottom chord between the chord and wall. The joist are solid. We don't have any strongbacks mid span but may add in for extra reassurance. Edited January 23, 2018 by Alexphd1 Link to comment Share on other sites More sharing options...
readiescards Posted January 23, 2018 Author Share Posted January 23, 2018 Wow 147mm wide @ 400mm centres looks a thousand times better than mine - (even though my span was only 4.5m) Link to comment Share on other sites More sharing options...
Alexphd1 Posted January 23, 2018 Share Posted January 23, 2018 Before we packed them out there was big bounce. Link to comment Share on other sites More sharing options...
Gone West Posted January 23, 2018 Share Posted January 23, 2018 3 hours ago, Alexphd1 said: I was getting slightly worried reading this thread as we are installing our wolf posi joist this week. Our joist are designed to hang by top chord on a 47mm wide batten one side and 100mm other side. Span is 5.6m WS250 joist that is 147mm wide @ 400 centres. No steel joist hangers. We have tightly packed the bottom chord between the chord and wall. The joist are solid. We don't have any strongbacks mid span but may add in for extra reassurance. No need to worry, ours are hung by the top chord on a 50mm ledger plate both ends. The span is 5.9m and the chords are 122mm wide and are at just less than 400mm centres. They are tied with a 100 x 50mm strongback. Link to comment Share on other sites More sharing options...
Simplysimon Posted January 23, 2018 Share Posted January 23, 2018 @readiescards do you still have drawings with the spec for the floor? Link to comment Share on other sites More sharing options...
readiescards Posted January 25, 2018 Author Share Posted January 25, 2018 @Simplysimon I've managed to find this drawing. It does not give much detail so I've asked the manufacturer to see if they can send me a PDF version of the calculations - some 40 pages! Link to comment Share on other sites More sharing options...
Simplysimon Posted January 25, 2018 Share Posted January 25, 2018 going by the wolf site an opening is specced as below ok it's a stair opening, but it's still an opening and the trimmer is a good bit bigger 1 Link to comment Share on other sites More sharing options...
Nickfromwales Posted January 25, 2018 Share Posted January 25, 2018 Yup, they could have at least sistered two bits of the smaller trimmer joist together to beef it up Link to comment Share on other sites More sharing options...
PeterW Posted January 25, 2018 Share Posted January 25, 2018 Right... Here is where a lot of your issues are : The red circle shows two things. Firstly that the hanger is not connected at the base or the face so its free to twist when any load is put on the bottom. The blue circle shows that the hanger and the posijoist are incorrectly fitted. The hanger should either fit the full face of the trimmer, or have a tab under the trimmer and "legs" wrapped over the top. It also looks like the hanger is missing a few nails. Any weight on that joist is going to twist the trimmer out of line and allow it to bounce. Looking at it in detail you could potentially get a block down the side of FT02 and FG01 from your layout that would brace the trimmer against the wall and stop it twisting although that wouldn't sort that trimmer issue. I would be asking the builder what was supplied - and also checking if that came from the manufacturer as B01 definitely looks wrong ! 3 Link to comment Share on other sites More sharing options...
Simplysimon Posted January 25, 2018 Share Posted January 25, 2018 @PeterW and as stated previously, look to the top of the trimmer above your red circle, it's short there too, either that or it's a trick of the lens 1 Link to comment Share on other sites More sharing options...
Nickfromwales Posted January 25, 2018 Share Posted January 25, 2018 54 minutes ago, Simplysimon said: @PeterW and as stated previously, look to the top of the trimmer above your red circle, it's short there too, either that or it's a trick of the lens +1. Thats a shocking bit of work there. Link to comment Share on other sites More sharing options...
PeterW Posted January 25, 2018 Share Posted January 25, 2018 1 hour ago, Simplysimon said: @PeterW and as stated previously, look to the top of the trimmer above your red circle, it's short there too, either that or it's a trick of the lens I wondered that but if the joists are all the same depth then it would mean the middle joists were lower ... But it’s still not right !!! Link to comment Share on other sites More sharing options...
Simplysimon Posted January 25, 2018 Share Posted January 25, 2018 that's why i reckon it may have been lifted level, if thats the case the bottom chord doesn't touch at all! best case it was packed level. definitely not right!! Link to comment Share on other sites More sharing options...
Mr Punter Posted January 26, 2018 Share Posted January 26, 2018 I think B01 should be the same depth as the others but this was not supplied as part of the package so the builder got the nearest size conventional joist from a merchant, was unsure of how to make it fit, then sort of split the difference. Also I would be interested to know if the decking was D4 glued and screwed? Link to comment Share on other sites More sharing options...
readiescards Posted January 26, 2018 Author Share Posted January 26, 2018 Thanks all, I've yet to try bracing that area from underneath to see what effect it has. I did notice in a separate part of the building not all the holes in the hangers where filled with nails - so suspect this floor (fitted by same builder) likewise is missing nails - as pointed out by @PeterW Nor can I see in my various photos any sign of packers to brace joist against the wall once installed. (If I understand correctly the implication is that there should be some). I now have the 41 page pdf document of posi-joist calculations but I'm reluctant to post it publicly while this floor issue remains. I would really welcome someone with a bit of posi-joist knowledge having a quick look through it if anyone has time, just to confirm the design is acceptable. That would be really appreciated. Link to comment Share on other sites More sharing options...
readiescards Posted January 26, 2018 Author Share Posted January 26, 2018 15 hours ago, Simplysimon said: @PeterW and as stated previously, look to the top of the trimmer above your red circle, it's short there too, either that or it's a trick of the lens I think it is a trick of the camera as it looks level in the photo in this post: Link to comment Share on other sites More sharing options...
readiescards Posted January 26, 2018 Author Share Posted January 26, 2018 is the gap between joist and wall normally? Link to comment Share on other sites More sharing options...
readiescards Posted February 1, 2018 Author Share Posted February 1, 2018 MiTek have check all the calculations and the design and report 'Based on the loadings applied to the joists, which appear appropriate for a typical domestic dwelling, we have found that all of the joist designs conform to the relevant design codes.' So they seem happy, suggesting manufacture or installation issue - or 'appropriate for a typical domestic dwelling' is below my own expectations Link to comment Share on other sites More sharing options...
readiescards Posted February 1, 2018 Author Share Posted February 1, 2018 Still curious if these joist end gaps are normal though Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 2, 2018 Share Posted February 2, 2018 Normally the ends are packed to take the compressive load in the lower member, and the upper member has to be fixed so that it can take a tensile load. If there are gaps like that at the bottom, then as I think I mentioned much earlier in this thread, that could well be a contributory factor. I think one issue may be that some builders don't realise that any composite joist, like posijoist, I beam or whatever, has slightly different end fastening requirements to a solid timber joist. 1 Link to comment Share on other sites More sharing options...
readiescards Posted June 26, 2018 Author Share Posted June 26, 2018 BCO did final inspection yesterday and he said something along the lines of 'I've never experienced a floor like that in a modern house before' ? Link to comment Share on other sites More sharing options...
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