Floor joists on single storey extension

[ColinHardie]

Hi all,
I have been taking a look at the work done by the builders appointed to build rear single story extension to my house. The length of the extension is around 6.8 meters. We are now 2 weeks down the line and I have been looking at what they are doing with regard to the floor trusses.

I noticed that on my plans that I have a small 'sleeper' wall at the mid point of the single storey extension to the rear (presumably to rest the trusses on). This wall, and indeed the foundations to rest the wall on are absent from what the builders have built thus far. The joists are supported at mid-span from timbers supported directly from the solum (see attached images).

This to me does not seem right and I was wonder if anyone can tell me whether this is OK both from a structural standpoint and what has been agreed from engineers report perspective (to me, any deviation from what is in the plans is a no no)?

If this is a big problem, can anyone tell me an appropriate course of action with regard to resolving this as I have already approached the builders and they stated that "this is the way we do it".

Regards
Colin

Untitled

• ColinHardie
• 5 Feb 2009
• 2

Mid point trusses support

Untitled

• ColinHardie
• 5 Feb 2009
• 3

Mid point trusses support

 

[DAZB]

This needs to be taken out and done properly in my opinion. There is direct contact between timber and the oversite concrete and no obvious evidence of any DPM. In time if the upright timbers rot, split or move it will be useless and the floor will sag. In their favour they have doubled up the joists but the fact remains that it is not to spec and is therefore not right. I would say ring the Building Inspector and get him to see it asap and that way you can let him tell the builder it is not acceptable. By the way what purpose does the OSB have ?

 

[ColinHardie]

Hi, Thanks for the response.

The builders did say that they have used a DPM between the oversite concrete and the timber...I will check again to make sure. They also said they were going to put additional bolts between the doubled up joists and since I have pulled them up about it have conceded to say the will add additional breeze blocks underneath each joist (quite why the never done this in the first place is anybodies guess). Still not the foundations/wall in the plan but if it removes the risk of rot and a sagging floor then surely it must be better.

The OSB is not nailed to anything, it is just for them walking around on whilst the build the additional structure.