Structural Issue?

[000_dave_000]

I purchased a property a few months ago that had an internal garage knocked through to extend a lounge. This involves removing a load bearing wall and installing an RSJ. The work was completed four years ago and has a buildings regulation completion certificate.

When purchasing the property I was led to believe this should remove any doubt over the structural integrity of the house and no structural survey is needed (the house is only 15 years old).

However, after living in it for a few months there are a few things that concern me:

1. I've noticed a couple of cracks, max 1mm thick and between 10 and 15 centre meters long, coming from the doorframe on the floor above where the work was completed.

2. Doors on the floor above perpendicular to where the wall was knocked through are stiff to open

3. Doors on floor above parallel to where the wall was knocked through don't meet up with door frame perfectly

4. Floor boards around where work was done are very creaky!

I was just wondering if anyone had any experience with this and whether I should be worried? I'm considering getting a structural engineer in to take a look and ease any fears I have, but wanted to make sure I wasn't worrying over nothing...

 

[gingerbiscuit]

Who suggested it didn't need a survey? A 15 year old house could suffer from bodged building work just like any other. I wouldn't panic though just keep an eye on the situation to make sure it's old movement from when the work was originally done. If you are worried post some pics on here and I'm sure you'll get all the advice you need.

 

[000_dave_000]

Thanks for the quick response! The work was done four years ago, but in hindsight I do wish I'd done a survey... both our solictitors and the people who did the homebuyers report said it wasn't necessary.

I've attached an image of the widest crack as suggested

 

[bernardgreen]

Were the doors stiff to open when you viewed the house before purchase and then have become stiff since you moved in ?

If they have become stiff since you moved in then a structural survey would be highly recommended.

a buildings regulation completion certificate.

sadly these can be based on the builder's word that the structural plans passed by building control were adhered to. Sometimes builders can make a mistake ( or cut costs ) and not do exactly as per the plans. A pad stone ( the bit the new RSJ rests on ) may be crumbling and that would give rise to the signs you are seeing.

 

[000_dave_000]

They were stiff when we moved in four months ago, it's only really one door that's significantly stiff, but the area it's stiff is between door and floor. The door is directly below the RSJ.

The cracks I only noticed a month ago, but to be honest it's quite possible they were there when we moved in but just didn't see them... I've monitored them for a month (which I realise probably isn't enough time!) and they haven't grown yet.

Thanks for all your advice, really appreciated

 

[tony1851]

A pad stone ( the bit the new RSJ rests on ) may be crumbling and that would give rise to the signs you are seeing.

Why would a padstone crumble?

 

[bernardgreen]

Why would a padstone crumble?

Because it wa the wrong material and unable to take the pressure exerted on it. Builder cutting costs is one reason the m,aterial could be wrong

 

[tony1851]

Builder cutting costs is one reason the m,aterial could be wrong

If he'd used blancmange as a padstone I agree it might not work, but padstones are formed in high-strength concrete.
If there has in fact been any settlement (which of course we don't know), it would be the material under the padstone which fails.

 

[bernardgreen]

but padstones are formed in high-strength concrete.

or shaped granite or other natural hard wearing strong material when the job has been done properly.

 

[wessex101]

Sounds like there has been some very slight movement but not something I would worry about just yet.

It could just be normal deflection in the steel beam or slight dropping of the wall if it wasn't propped and packed correctly. Probably just needs some making good, fill the cracks and redecorate, ease the door etc.

 

[tony1851]

or shaped granite or other natural hard wearing strong material when the job has been done properly.

In theory - yes, of course, but in practice......? but not seen many granite padstones at Jewsons lately

 

[John D v2.0]

Having seen how one builder "propped" up, and the resulting cracks, I'm guessing in your case the builder made up his own method of temporary support which wasn't very good.

 

[000_dave_000]

Thanks for all your comments guys, they've been really helpful!

Seems like the most likely explanation based on your responses is it wasn't properly propped up when the work was originally done. In this case, am I right in saying the movement would all have happened while the work was being completed and in theory shouldn't move any further?

 

[^woody^]

That crack is from shrinkage of the plaster and not movement.

 

[Millwright]

If he'd used blancmange as a padstone I agree it might not work, but padstones are formed in high-strength concrete.
If there has in fact been any settlement (which of course we don't know), it would be the material under the padstone which fails.

This is something which has got me thinking about something.

Given why engineering bricks or a concrete block should be used as a pad stone, why are the regular bricks allowed to be left underneath?