Structural Issues - structural engineer or building control

[tfman]

Hi,

Last year we moved into a three storey Victorian terrace (built around 1840), with a parapet gutter at the front of the property.

The plaster work on the front room on the top floor was incomplete disrepair, and so we decided to take it down, go back to the brick and then completely re-plaster. Upon removing the plaster I found that one of the ceiling joists was rotten. I bought this up in a previous post, //www.diynot.com/forums/general-diy/broken-ceiling-joist.397572/#3063562 where you can see some photos of the rotten joist.

I thought it best to get a damp and timber surveyor in to have a look. I've now down this and it seems like there is a lot of work to do, and I would appreciate some advice on what to do next.

Here is an image of the front wall from the inside.

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• tfman
• 25 Jul 2014
• 1

There is a lot of timber built into the wall, including the window lintels and the wall plate, where the rafters & joists meet the wall. There is also some timber built in around half way up the wall, which was used to fix timber battens to the wall for the laths. It is probably quite difficult to see in the photo, so I've highlighted the built in timber in this photo. (Well, I've tried to. My artwork leaves something to be desired)

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• tfman
• 25 Jul 2014
• 1

The surveyors findings were

A softwood wallplate is built into the front wall, and this supports the ceiling rafters and the roof rafters as well as parapet gutter boarding.

Several ceiling rafters were found to be loose/detached, and some suffering wood rot.

Counting from right hand end, the following rafters have problems as indicated :

No 4 : rafter too thin
No 7 : loose at end and rot damaged
No 8 : end of rafter rotten.
No 10 : end of rafter rotten
No 13 : end of rafter rotten

Easiest to simply replace defective rafters complete as timber not unduly expensive.

The built-in wallplate is subject to rot, mainly at its base, at a number of locations.

In addition, The left hand window’s timber lintel is rotten on the top, with wooden end
bearing pads rot affected, and the right hand window’s left hand timber bearing pad has rot underneath.

There are horizontal timbers at mid height of the windows, and these members are also
damaged by wood rot.

So in effect all built in timbers need replacement.

The parapet gutter boarding seemed in reasonable order where checked.

The two top floor windows are plastic double glazed sliding sash type.

They have been rather lazily fitted. There are huge voids between the original brick recesses and the new frames. This in effect in my opinion weakens the window openings, as a traditional box frame would help brace up and support a brick opening. Brickwork at this level has a noticeable bow and must in my opinion be tied in.

His suggested remedial work is as follows

Structural Assessment – Seek further advice from a local Structural Engineer who will probably agree with my suggestions for lateral restraint etc.

a) Floors – At very least - Additional bracing required.

b) Front Elevation bowing – Window openings need bracing up. You might opt, for example, to take out the two top floor windows and if finances allow – replace with traditional box frames.

c) Consider fitting elbow ties – say two, at each front wall corner. You can also use resin bonded steel helical ties ( EG by HELIFIX)

Note that some contractors would have re-built the top floor front wall due to the combination of defects.

Top Floor Timberwork

Replace complete the built in wallplate – ideally with dpc protection tacked to back and base. The wallplate can be fitted with ‘L’shaped strapes.

Replace defective or undersized ceiling joists (at least 4No)

Take out all embedded timber plates on front wall. Install two pre-cast concrete lintels.

Brick up timber built in bearers.

At the end of the report he states that

NOTE : In view of the range of structural repairs needed for the top floor – I advise you to obtain a building notice and liaise with the local authority building inspector – and by doing this you may obtain structural advice from the LA without needing to employ your own structural engineer. I have to advise you do this being a chartered surveyor with professional responsibilities. This case involves more than just dampness issues as you
can appreciate. I can’t be involved in site supervision due to the distances involved.

When we moved in the rendering behind the down pipe on the front wall of the property was blown, and this was causing penetrating damp. This has now been rectified with new rendering.

The surveyor wasn't able to get up to the parapet gutter, so I don't know if this is an issue or not. As everything else in this house has had issues, I would suspect that it is an issue.

Anyway, I would appreciate some guidance on what to do next.

I was thinking of following the surveyors suggestion of building notice, and thereby getting advice on the structural issues from the LA. Is this a reasonable course of action? Should I submit it before or after I've found a builder? What are people's experiences with building notice and LA's?

I've had a look at building notice and full plans applications. It seems that building notice is mainly suitable for people who know what they are doing (in terms of building
regulations etc) which I don't.

I suppose the other alternative it to get a local structural engineer in myself, and get them to check whether the top of the front wall needs to be rebuilt. Do you think doing this, and going down the route of full plans application would be a better bet.

Sorry for the long post, but any advice would be appreciated.

 

[ree]

tfman,

you do yourself no favors by posting in three different forums at different dates.


You were last, extensively advised about the rear elevation when you suddenly disappeared from your own thread - you now re-appear with the front elevation as the focus of your concerns.

Whatever, you should gather together all the relevant information, from any source, regarding the defects at your property - tie annotated pics into the "file".

Was the surveyor, who's report you post, a RICS surveyor or something else? Did he include pics or sketches in his report?

Why wasn't the whole property, including the roof and gutterings, thoroughly surveyed?

Bldg Regs are the law not an option. Why the ref. to planning?

 

[tfman]

You were last, extensively advised about the rear elevation when you suddenly disappeared from your own thread - you now re-appear with the front elevation as the focus of your concerns.

I didn't `disappear', I just hadn't put an update up yet. I've been busy with a week long job interview. I've now had the back gutter done, and will update the other post. Thanks for the help with that btw. It was greatly appreciated.

Was the surveyor, who's report you post, a RICS surveyor or something else?

He was an RICS surveyor, but he was a damp and timber surveyor, and not a structural surveyor.

Why wasn't the whole property, including the roof and gutterings, thoroughly surveyed?

We had a survey when we first buying the property, and it bought up none of the issues that we've had, i.e. the blown rendering, the leak at the back and the parapet gutter. Basically the survey was a joke.

When we first moved into the property we realised we had some problems and got a damp and timber surveyor. Again, this guy was a joke and told us that the leak at the back was historical and that all necessary walls should be tanked. I since found out that he was a member of the PCA, and I should have stayed well clear.

I then found this final surveyor, who I was fairly happy with. He couldn't tell everything about the front of the property, i.e. about the structural aspects of the front and whether the parapet gutter was an issue or not, but otherwise he was helpful.

I was still under the impression that the leak at the back was historical when this final surveyor came around, so I asked him to focus on the front of the property.

Bldg Regs are the law not an option.

Sure, what I meant was that I want to make sure any builder I get works to building regulations.

Whatever, you should gather together all the relevant information, from any source, regarding the defects at your property - tie annotated pics into the "file".

Sure, I will do that.

 

[ree]

Perhaps you could post pics of the front elevation and redline the area with the bulge(s)? And maybe do a similar pic from the interior?

Has the whole front elevation been rendered, or only patched behind the RWP?

What is wrong with the floors - which floors? What does he mean by additional bracing?

"elbow ties" and "front wall corners" - i can guess what he means but its not clear.
Installing "helical ties" - where?

Are the pre-cast lintels prescribed for the window openings in the pic?

Parapets and parapet gutters are notorious for penetrating damp - it appears that the damage to the rafter tails and wall plate is most likely coming from that source.

The roofer you've already used might be asked to inspect the front parapet and gutter - ask for pics of his findings. Thing is, its no use bringing in anyone else until you have solid info about the parapet etc.

Removing a wall plate and rafters, with a tiled roof, a wall bulge and perhaps faulty floors below, could be straightforward or quite tricky - it would have to be thought thro, and a heads up (post parapet inspection) with the building inspector could really help. No Blg Regs yet, just a chat and perhaps a visit?

 

[tfman]

Hi,

Thanks for the response. Sorry for the late reply. I have been away for the last week.

Perhaps you could post pics of the front elevation and redline the area with the bulge(s)? And maybe do a similar pic from the interior?

Sure, I will do that in the next day or two.

Has the whole front elevation been rendered, or only patched behind the RWP?

We had the whole front elevation re-rendered. We had an EPS external wall insulation system installed with a thin coat render. In hindsight I think this was a mistake, and a breathable render should have been used. This has been quite a steep learning curve for me.

What is wrong with the floors - which floors?

I believe the floor joists on the top floor are a bit on the thin side for a floor. There is no rot in these though.

What does he mean by additional bracing?

"elbow ties" and "front wall corners" - i can guess what he means but its not clear.
Installing "helical ties" - where?

Good question. I will have another look at the report and get back to you.

Are the pre-cast lintels prescribed for the window openings in the pic?

Yes. The surveyor also recommended that the current windows should be replaced with box windows. There is currently a void between the uPVC windows and the wall. An example is given in the photo below. The new windows would fill in these voids and, according to the surveyor, would help shore up the wall.

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• tfman
• 5 Aug 2014
• 1

[code:1]
Parapets and parapet gutters are notorious for penetrating damp - it appears that the damage to the rafter tails and wall plate is most likely coming from that source.
[/code:1]

That is my feeling too.

[code:1]
The roofer you've already used might be asked to inspect the front parapet and gutter - ask for pics of his findings.
[/code:1]

I was thinking of doing that, but I didn't know whether to look into the structural aspects of the problem first.

I suppose there is no harm in asking him to have a look. The renderer did a botch job when he replaced the coping stones. He is coming back to remedy the work within the next month. I will ask the roofer to have a look while the renderer has scaffold up.