Author Topic: NHBC standards for chipboard floors on I-joists?  (Read 38351 times)

0 Members and 2 Guests are viewing this topic.

Mugen

  • New Member
  • *
  • Posts: 14
NHBC standards for chipboard floors on I-joists?
« on: January 17, 2014, 12:36:48 am »
I bought a 4 bed detached from Redrow Homes (big mistake) around 2 years ago and like many, I have had numerous problems with the workmanship and have had to endure some appalling customer service!

One of the main problems we have is with creaking/cracking noises from floors/ceilings. Basically, when someone is walking around in a room on the first floor you can hear some kind of creaking within the room but at the same time these noises produces cracking type noises in the room directly below (appears to be from ceiling).

The floor construction is 22mm thick chipboard set on 240mm deep x 45mm TJI style timber joists set out at 600mm centres. It has been discovered that the boards have not been fixed down properly e.g. random patches of glue on joists, glue on the boards but completely missing the joists and like the odd screw somewhere. Limited presence of noggins, noggins too short, and overall poor workmanship.

Does anyone know what the NHBC standard/specification for fixing chipboard floors?
They should be glued and screwed?
Noggin requirements?
Any other information that I should be aware of?





New Home Expert

  • Global Moderator
  • Expert
  • *****
  • Posts: 921
  • Country: england
  • Expert advice for new home buyers
    • New Home Blog
Re: NHBC standards for chipboard floors on I-joists?
« Reply #1 on: January 17, 2014, 10:48:29 am »
The relevant NHBC standards regarding chipboard flooring are:
"6.4 - S14
Flooring shall only be fixed when the dwelling is substantially weathertight
6.4 - S15
The length of nails should be 2½ times the thickness of the decking.
The ends of adjacent boards should be square. Joints should be staggered and supported on noggings or joists.
Temporary wedges and packings at the perimeter should be removed after the floor decking is complete.
6.4 - S18
Chipboard flooring shall be of the type and thickness specified
Only moisture-resistant, Type P5 chipboard to BS EN 312 should be used for flooring. Joist centres should not be greater than 450mm for board thickness of 18/20mm and 600mm for boards 22mm thick.
6.4 - S19
Chipboard flooring shall be securely fixed
Chipboard should be supported and fixed in accordance with manufacturers' instructions, using either
flat-headed ring shank nails minimum 3mm diameter and of length 2½ times the thickness of the chipboard, or screws.
Edges at room perimeters should be supported on joists or noggings.
Fixing centres to joists should be:
200mm - 300mm centres around the board perimeter
400mm - 500mm centres on intermediate supports.
Expansion gaps should be not less than 10mm wide where boards abut a rigid upstand. For larger areas of boarded floor a wider gap may be needed at upstands and intermediate expansion gaps equal to 2mm per linear metre of floor provided.

Tongued and grooved chipboard:
Boards should be laid with long edges at right angles to joists
Short edges should be supported on joists or noggings.
Projecting ends of boards should be cut back to form a butt joint on a joist.
To reduce squeaking, tongued and grooved joints between boards should be glued and the boards should be glued to the joists. A suitable polyvinyl acetate (PVAC) adhesive should be used."


The standards say "should" be glued not "must" be glued.
TJI joists must be installed strictly to the manufacturers' guidelines and design.
It may be that the joist spans are too large or joist section is too small, meaning you get excessive deflection in the joists of the larger rooms 
It would also be useful for you/your engineers can get to see a copy of the TJI floor joist design.
New Home Blog - New Home Expert is committed to providing help and advice for people having issues with their new homes and difficulties with house builders as well as helping potential buyers reduce the risk of possible problems if they do buy.


Mugen

  • New Member
  • *
  • Posts: 14
Re: NHBC standards for chipboard floors on I-joists?
« Reply #2 on: January 17, 2014, 04:54:24 pm »
Thanks for the reply.
I know the joist manufacturer is Steico so will need to check out the specifications!

Regarding "TJI joists must be installed strictly to the manufacturer's guidelines and design"

I am just wondering would it be possible to post the extract along with the section numbers as it will come in handy when I argue with Redrow and the NHBC?

New Home Expert

  • Global Moderator
  • Expert
  • *****
  • Posts: 921
  • Country: england
  • Expert advice for new home buyers
    • New Home Blog
Re: NHBC standards for chipboard floors on I-joists?
« Reply #3 on: January 18, 2014, 08:14:53 am »
The NHBC standards state:
"SITEWORK STANDARDS
6.4 - S1 All sitework shall:
(a) meet the Technical Requirements
(b) take account of the design
(c) follow established good practice and workmanship"

6.2 - S1 (with regard to timber frame components) states:
"All relevant information in a form suitable for the use of site operatives should be available on site before construction starts including:
  • full set of drawings
  • materials specification
  • fixing schedules
  • nailing details
  • manufacturers' recommendations relating to proprietary items."

You shouldn't need to quote specific NHBC standards as the industry knows that manufacturer's designs and recommendations must be strictly followed.
New Home Blog - New Home Expert is committed to providing help and advice for people having issues with their new homes and difficulties with house builders as well as helping potential buyers reduce the risk of possible problems if they do buy.

TaylorWimpeyDidThis

  • New Member
  • *
  • Posts: 24
Re: NHBC standards for chipboard floors on I-joists?
« Reply #4 on: January 18, 2014, 12:57:42 pm »
Hi Mugen

We have exactly the same issue with our Taylor Wimpey House - all of the issues with the floors were noticeable when we moved in 2 months ago and have got significantly worse as the house has "settled"

When someone is walking around upstairs, the noise is a very distinct and loud cracking sound and when walking on the thresholds of the rooms upstairs, the cracking and creaking is deferred a few feet away.

One of the smaller rooms has Amtico installed and you can physically feel the movement in the floor, as well as hear it! Interestingly, we have been advised that to sort the other rooms upstairs, the carpet can be lifted and fixed from above. But where Amtico is laid, rather then remove and reinstall the Amtico (at additional cost) - Taylor Wimpey will remove the ceiling underneath and go in from the ground floor and then redecorate the ceiling - although I'm scratching my head as to how they will fix the boards down from underneath?

Within a week of moving in, the outlines of the floorboards could be clearly seen through the plaster ceiling in the living room, even though the room above is not used!

We know that our house was exposed to very wet weather before the roof went on and also that it was rushed - so I guess only a closer look will determine what lies beneath.

I'd be very interested to hear how you get on, please keep us posted

<a href="http://www.youtube.com/watch?v=1Zr8s7gsrKs" target="_blank">http://www.youtube.com/watch?v=1Zr8s7gsrKs</a>


 :)

Mugen

  • New Member
  • *
  • Posts: 14
Re: NHBC standards for chipboard floors on I-joists?
« Reply #5 on: January 18, 2014, 11:23:07 pm »
Hi New Home Expert,

Thanks for the information will sure come in handy and the quest to beat the developer!!

Mugen

  • New Member
  • *
  • Posts: 14
Re: NHBC standards for chipboard floors on I-joists?
« Reply #6 on: January 19, 2014, 01:20:52 am »
Hi TaylorWimpeyDidThis,

I had the NHBC meeting with the builder and conveniently enough they showed up at my door at the same time (read many of these stories before!) I found the NHBC rather friendly with the builder and one could easily mistake them to be friends or colleagues, they also addressed each other by first names (should I have been surprised?  :-\). I felt that the NHBC investigator was on the developer's side for the most part and wasn't interested on what I had to say or I what wanted to show them (I wonder why???). They listened to the developer on what sections of the floor should be opened and I didn't get much of a say to be honest (I guess by this time you are not surprised either eh?  :D)

However, I had an expert witness from the industry at the meeting who questioned some areas of floor and commented on bad workmanship when sections of it was opened up.

In the end the NHBC ruled in my favour, that the builder must relay the floors in the bedrooms but I felt that the investigations which took place were not adequate and thorough enough to conclude the work which has been ordered. I also overheard the NHBC say to the builder something along the lines of "you can't be seen to not do anything," whilst they were discussing amongst themselves (I can only assume that this came about because my expert witness had pushed them and that had some valid points on the failure of the floor!)

There was no discussion with me and they had already decided among themselves on what is going to be done whilst they had a little whisper meeting outside. I didn't get to have a say on what was going to happen or any real opportunity to ask anything as they were leaving. It was decided that the builder is to arrange works with me even though I did not have clear information on exactly what needs to be done, I was just told they know what to do at first until I questioned but even the answer was very vague.

It may appear that I have beaten the builder in this instance but I truly believe that I only got a result as I had a professional on my side, if not for that I think the builder would have won and walked away with a smirk. I do not really have much faith in the work which has been ordered, not only because the way I felt I had won but because the investigations were not thorough, plus I have had sections of the floors opened in one of my other rooms in the past, where the builder glued the boards down and added quite a few screws to secure the floor but did not make any difference (I actually mentioned this in the meeting too, but it was ignored).  I have also read that others with similar issues had new boards installed but didn't rectify the issue. Moreover, I have spoken to a few people who experienced these problems who got a result with either the developer or NHBC by installing independent ceiling systems e.g. resilient bars or additional joists being inserted between the existing one to decouple the ceiling. So I some how feel that my victory maybe short lived.

I hope you get your issues sorted out and I will keep you posted as the event unfold.

Good Luck!






New Home Expert

  • Global Moderator
  • Expert
  • *****
  • Posts: 921
  • Country: england
  • Expert advice for new home buyers
    • New Home Blog
Re: NHBC standards for chipboard floors on I-joists?
« Reply #7 on: January 20, 2014, 08:21:59 am »
Regarding the work that has been agreed will be done, the NHBC should (must) write to you following their inspection, detailing what was found wrong and what is proposed to put it right.

It makes sense for the NHBC and builder's representative to call on you together. otherwise one of them would be kept waiting.
It is also highly possible that they would know each other, especially if the builder's customers are always complaining to the NHBC!  It is polite  to be on first name terms too.
Perhaps the builder's representative was a customer care manager and would regularly speak with NHBC claims inspectors.
I would believe it is human nature to try and limit the extent of remedial works, especially in someone's home and especially when any improvement may be unlikely or they are unsure of the cause and how serious the issues may be.

The NHBC is far from perfect and they do have some empathy with the house builders.
But consider how bad things would be if the NHBC did not exist to inspect and set standards and force builders to fix problems?

The main problem with timber floors is they get too wet before the home is weatherproof.  
In the old days, (before TJI and health and safety) the flooring was only installed after the roof was covered and the windows and external doors fitted!

TWDT
Drying out (aka "settling") is always more of a problem with timber frame new homes.
Floors cannot be fixed from underneath!  Taylro Wimpey are trying to save themselves a bit of money in not having to relay the Amtico flooring, even though taking down a ceiling will be more of an inconvenience for their long suffering customer!
New Home Blog - New Home Expert is committed to providing help and advice for people having issues with their new homes and difficulties with house builders as well as helping potential buyers reduce the risk of possible problems if they do buy.

Mugen

  • New Member
  • *
  • Posts: 14
Re: NHBC standards for chipboard floors on I-joists?
« Reply #8 on: January 20, 2014, 09:37:21 am »
Supposedly after work gets carried out and it does not fix the issue.
Do you know if I can have them out again to look at it say from a ceiling perspective since no investigations where carried out there?

Thanks again.


New Home Expert

  • Global Moderator
  • Expert
  • *****
  • Posts: 921
  • Country: england
  • Expert advice for new home buyers
    • New Home Blog
Re: NHBC standards for chipboard floors on I-joists?
« Reply #9 on: January 20, 2014, 10:41:36 am »
You can get them out as many times as it takes to fix the issue.
Especially now, as they have acknowledged and accepted that a problem needs dealing with.
But.........it is not an issue with the ceiling and taking them down is very messy! 
New Home Blog - New Home Expert is committed to providing help and advice for people having issues with their new homes and difficulties with house builders as well as helping potential buyers reduce the risk of possible problems if they do buy.

Mugen

  • New Member
  • *
  • Posts: 14
Re: NHBC standards for chipboard floors on I-joists?
« Reply #10 on: January 23, 2014, 02:10:16 am »
Just had my NHBC report back. The report states that the builder is to relay all the floors with new ones.
This is to be done by cutting out to approx 150mm of the room perimeter in All the bedrooms on the first floor and the landing too.

So my floors creak and the ceiling in the rooms below make a cracking noise as previously mentioned.
Below Bed 1 is the Lounge, Beds 2&3 is the kitchen/diner. Bed 4 is above the guest toilet and part of hallway and the landing is just over the hallway.

I have some concerns and want to seek opinion and advice. Basically there are 4 bedrooms in my house. The problems are in bed 1, 2 and 3 and subsequently the rooms below it. I actually don't have a problem with the landing or bedroom 4. But the NHBC have ordered for works to be done in those areas too.

I am in doubt if the landing and Bed 4 should be touched at all as I fear more problems maybe created! The old term "if it ain't broke don't fix" it springs to mind!

My dilemma is that if I ask for the work not to be done in these two areas and what they do in my other rooms doesn't fix the problems, I am worried that the NHBC will not address it further since I did not agree with what they suggested. However, as these two areas do not have any problems I don't see why it actually needs to be done there too.
Also as mentioned I didn't really get a say on what was going to happen, I was just basically told what is going to happen, in affect the report states as agreed works to be carried out etc etc.. Also bare in mind the builder is awkward and given that they have been instructed to do this they could very well refuse what I want since they like to make life difficult.

Would appreciate any advice or suggestions on what I should do about this and any potential problems or concerns I should take into consideration will be most welcome.



New Home Expert

  • Global Moderator
  • Expert
  • *****
  • Posts: 921
  • Country: england
  • Expert advice for new home buyers
    • New Home Blog
Re: NHBC standards for chipboard floors on I-joists?
« Reply #11 on: January 23, 2014, 11:03:23 am »
If the NHBC say that work needs to be done then I would advise all the work the NHBC says is done.
Even if there are not any issues in the areas you say at the present time, it doesn't mean there won't be in the future!

My guess is the NHBC inspector suspected (or the builder has confessed to him) that the joist installation may not exactly comply and they are insisting all the flooring is taken up so it can all be checked.  
In any event, new 22mm chipboard flooring will be better than the existing flooring.
My advice therefore would be to allow all the works to take place.

As it will not be possible for the all the flooring to be taken up in one go, Redrow should give you a timetable (a detailed programme and a method statement of works) indicating their proposals as to what rooms or areas will be taken up and replaced on specific days.  
You will need to make space for furniture to be moved and arrange for carpets to be taken up and replaced on a room by room basis. By the way, carpenters don't lay carpets and underlay!
You may also need new underlay if it has been stapled and damaged during removal. Make sure any new underlay is the best grade you (or Redrow!) can afford as this will help with insulation and impact noise.
You should also take time off so you or someone in your family can be there and see what is being done in your home.  Do not trust Redrow or their contractors or leave them unattended.

I would also suggest you take photographs of the joists in each area once the flooring has been removed.
As a section of flooring is remaining at the room perimeters, this must be supported on a continuous noggin one way and on a full floor joist the other.  As you have Steico TJI type joists the noggins should be supported on proprietary noggin clips, not just skew nailed!

Make sure the new flooring is 22mm thick T&G moisture resistant chipboard (Caberfloor TG4 MR P5 chipboard flooring boards 22mm x 2400 x 600mm)  
Check to see if the boards are being laid the right way up too, with all T&G joints  glued and boards screwed to the joists!   No nailing, as this could crack the ceilings.

Finally once all the work has been done and you are happy, you should consider a claim for compensation from Redrow for inconvenience and lost holiday leave.   They will say they don't pay compensation, but all house builders do!   None of this was of your doing.
New Home Blog - New Home Expert is committed to providing help and advice for people having issues with their new homes and difficulties with house builders as well as helping potential buyers reduce the risk of possible problems if they do buy.

Mugen

  • New Member
  • *
  • Posts: 14
Re: NHBC standards for chipboard floors on I-joists?
« Reply #12 on: January 23, 2014, 05:14:49 pm »
NHE,

Thank you for this! Given that my builder is awfully difficult do you know where I would stand should they refuse my request.

I also want them to supply me with a list of materials (manufacturer and part numbers) they will use.  Do you think that this is my right to know given they have had many opportunities to make things good in the past?

New Home Expert

  • Global Moderator
  • Expert
  • *****
  • Posts: 921
  • Country: england
  • Expert advice for new home buyers
    • New Home Blog
Re: NHBC standards for chipboard floors on I-joists?
« Reply #13 on: January 24, 2014, 07:24:46 am »
I think it is perfectly acceptable that you should ask what materials they are intending to use.
Any trust you may have had with Redrow has long since vanished.
The last thing you want is to have taken a day off, moved your furniture and carpets and then the wrong specification flooring is delivered or the wrong size noggins! (these should be 47 x 50mm sawn timber by the way!)

Be prepared for a lot of dust!  You could ask Redrow to ensure that the boards are cut using a saw with dust collection or the boards are cut outside (a problem if it's raining and it probably will be!) perhaps if you have a clear garage, the boards could be stored and cut in there to save the dust.

I would be amazed if Redrow refuse to co operate with your request regarding a detailed programme and a method statement of works.
You need this information to plan what you need to do!
As any refusal would be completely unreasonable and perhaps you should go through the NHBC, rather than Redrow regarding this!
New Home Blog - New Home Expert is committed to providing help and advice for people having issues with their new homes and difficulties with house builders as well as helping potential buyers reduce the risk of possible problems if they do buy.

Mugen

  • New Member
  • *
  • Posts: 14
Re: NHBC standards for chipboard floors on I-joists?
« Reply #14 on: January 24, 2014, 10:07:56 am »

As a section of flooring is remaining at the room perimeters, this must be supported on a continuous noggin one way and on a full floor joist the other.  As you have Steico TJI type joists the noggins should be supported on proprietary noggin clips, not just skew nailed!


Regarding this are you saying that the old board that remains must be sitting on these or just the new board that gets laid?