What’s the worst mistake you’ve made on your build?

[saveasteading]

17 hours ago, Adsibob said:

just bloody ugly.

There is another solution. Get an Architect to post-rationalise the design: a unique skill that makes good reading in Architects Journal. I can't really do it but something like:

The sweeping curves of the sustainably sourced local oak staircase juxtaposes aesthetically and figuratively with the harsh rectilinear oversail, referencing the comforts of modern life contrasting with the harshness of the outside environment.

If you can find a useful purpose for the corner of floor, then that will also take away some pain.

Then convince yourself you like it and most importantly...stop looking.

[SteamyTea]

2 minutes ago, saveasteading said:

.stop looking

Joo Janta 200 Super-Chromatic Peril Sensitive Sunglasses.

 

Zaphod Beeblebrox in 'The Hitchhikers Guide to the Galaxy' used sunglasses that turned completely dark at the first sign of danger, thus preventing him from seeing anything that might alarm him. The only drawback: he couldn't see anything, including where he was going!

 

 

[raz_build]

Trusting next door neighbour builder and ending up doing the single block wall after strip foundation was done.  Just realised how naive we were until the building inspector questioned on joist span and luckily I was present. SE mentioned the joist span at 350mm, we ordered the material to do it at 300mm and the builder did at 600mm later showing some online tool calculations. Even for warm roof he was using 18mm osb board at top layer saying taping will air tight it but initially was told will do with caber-deck.  Also we were paying above market price in midlands for the work done but was convinced that we will save by doing the works together.

 

Went back to SE and he rejected the 600mm span but okayed for single block with EWI, amended the plans. Now fighting it out to get the work to be corrected for the payments already made so far.

They were also doing the outbuilding and if we compare both works there are major differences. Cavity wall with good insulation, joists at right spans etc for their building.

 

Not sure how someone can sleep by doing a loss to others and making gains from it that to being a neighbour. Lot of lessons learned and hopefully we correct them without incurring major losses.

 

Back to market to find right professionals for the rest of the work.

[Jilly]

Architect's technician forgot the bat membrane and specified breathable instead of F1 bituminous, so everything had to be respecified (bats' feet get tangled in the polyester and they die.) Had to have PIR instead of the lovely sheep's wool because of the 50mm gap needed we lost some insulation depth.

 

A designer friend visited part way through and said 'You need to double the length of the vaulted ceiling area'. After a sleepless night, I realised she was absolutely right. We needed more SE drawings done, wasted time, builder requoted an awful lot extra and I was over a barrel. But anyway, I'm glad we did it, it looks good.

 

Edited March 13, 2022 by Jilly

[Adsibob]

23 minutes ago, Jilly said:

After a sleepless night, I realised she was absolutely right.

Maybe sleepless nights are rights of passage for us self builders…

[Jilly]

8 minutes ago, Adsibob said:

Maybe sleepless nights are rights of passage for us self builders…

Tell me about it! It's a nightmare sometimes, if you will excuse the dodgy pun. 

[Andehh]

1 hour ago, Jilly said:

Architect's technician forgot the bat membrane and specified breathable instead of F1 bituminous, so everything had to be respecified (bats' feet get tangled in the polyester and they die.) Had to have PIR instead of the lovely sheep's wool because of the 50mm gap needed we lost some insulation depth.

 

A designer friend visited part way through and said 'You need to double the length of the vaulted ceiling area'. After a sleepless night, I realised she was absolutely right. We needed more SE drawings done, wasted time, builder requoted an awful lot extra and I was over a barrel. But anyway, I'm glad we did it, it looks good.

 

 

Our of curiosity, who paid for the PIR & adjustments due to the bat's feet miss? 

[SteamyTea]

52 minutes ago, Jilly said:

a nightmare sometimes

I have them. A customer who never gets served.

[Jilly]

1 hour ago, Andehh said:

 

Our of curiosity, who paid for the PIR & adjustments due to the bat's feet miss? 

Me! I stupidly changed from the original architect to a friend who is an architect's technician hence loads of problems I naively didn't anticipate when wanting to give him the work. He helped me a lot when I was renovating a previous house and became ill, so what goes around comes around.  I'm not the litigious type. 

[Gus Potter]

12 hours ago, Adsibob said:

As far as I can see, all steel 10 is doing is connecting 9 to 11. Two thirds of 11 is holding up the sky light, but I’m not sure Why steel 11 needs to project beyond where it connects with 12. Maybe

Hi all.

 

I can't quite see where all the supports are to the steelwork but there are plenty things that could be going on here and the SE looks like they have spent some time thinking this through. It's looks quite elegant really even though you have a bit of cantilevered floor that with hind sight you may not have chosen at the Architectural stage.

 

Let's start with the basics. A steel beam is designed for "pure bending" called its moment capacity (Mc). This is often where the steel starts to yield and fail but the beam does not distort or twist sideways. Beams can also fail in buckling where they just twist and distort and collapse suddenly. Often you find buckling (Mb) is the governing criteria. We call this (Mb) the buckling capacity of the beam. Long beams buckle easily so what we do is to fix floor joists, floors or other beams to them to prevent them from distorting / twisting / moving sideways and thus we increase the buckling capacity as we shorten what is called the effective length.. that is simplistically the distance between restraint positions. If we do this well we can in cases increase the buckling capacity up to the Mc capacity and thus get most bang for our buck.

 

Lets start with beam 8 and lets assume there is not much restraint from the floors as the joists span beam 9 to 7a. The SE may be using quite a stiff connection from beam 9 to 8 to stop the twisting / provide torsional / twisting restraint to beam 8 thus increasing it's Mb (buckling capacity) significantly. If you don't do this then often you need a heavier and deeper beam. They may also be using beam 12 to further reduce the effective length of beam 8.

 

As you come up the stairs on your left hand side there is the stringer with spindles above and behind the stringer there is a space before you seem to find the first potential support. It actually looks like the end of beam 11 is supported by beam 7a. Thus beam 11 spans from 7a to beam 10.. it is beam 10 that is holding up one end of beam 11, 7a the other.

 

Now for beam 10 to hold up the end of beam 11 it needs to act as a cantilever off beam 8, but if beam 9 was not there then beam 8 would just twist and it would fall down. I think the SE has designed a very stiff connection between beam 10 & 8 and 8 & 9 so that 9 & 10 act as a continuous beam, supported at one end by the outside wall and by beam 8 at the joint. Lastly you also find that where beam 9 rests on the wall the SE has made sure there is enough back weight to stop this end of beam 9 lifting upwards.. like ballast in a boat.

 

That looks like one possible hypothesis but a caveat is that we have not seen all the info, support detail and the global structural design.

 

Lastly the diagonal bracing. I have touched on a few but not all the facets of this but you can see that the steels will be doing a lot more than just carrying the basic loads. Everything will be wanting to twist, bolted joints will slip here and there so I think the SE has introduced the diagonal bracing to stiffen things up. Also the diagonal bracing may be providing global stability to resist wind loading.

 

In summary don't remove beam 10 or any other for that matter without asking your SE! Also don't let your fabricator / metal worker change the SE's connection design in any way without asking.

 

If you have read this far then thanks.

 

Gus

 

 

[SuperJohnG]

I have four so far...

 

1) Trusted the kit suppliers subcontractors to erect my house. 

2) drilled a borehole and didn't get enough water. 

3) just to be sure I didn't get enough water drilled another borehole...to waste some more money. 

4) my current mistake highlighted by the energy cap rise was not putting on the solar PV when I was getting roof slated. Silly mistake. 

[Radian]

1 minute ago, SuperJohnG said:

4) my current mistake highlighted by the energy cap rise was not putting on the solar PV when I was getting roof slated. Silly mistake. 

I've been beating myself up on this exact same mistake. But we were being slate roofed in 2019 and we had a hell of a time getting a competent contractor,  scaf. and materials organised as it was. To throw another half-dozen variables into the mix just seemed a bridge too far when the gains from PV were so much less tangible.

[Gus Potter]

Back on topic.

 

Probably telling my wife that our alterations would take 2 years to do worst case 3.. in 2017.. still not finshed.

 

Not overspecing (putting in more) the insulation.. just got the latest fuel bill in from Bulb.

[PeterW]

Assuming an existing building was square and level .. and then having to work around splayed walls and not pick it up until it was too late and a room built that has a pair of opposing windows and one is 35mm further back than the other as they were both measured from one wall and not checked ..!

[Adsibob]

1 hour ago, Gus Potter said:

Hi all.

 

I can't quite see where all the supports are to the steelwork but there are plenty things that could be going on here and the SE looks like they have spent some time thinking this through. It's looks quite elegant really even though you have a bit of cantilevered floor that with hind sight you may not have chosen at the Architectural stage.

 

Let's start with the basics. A steel beam is designed for "pure bending" called its moment capacity (Mc). This is often where the steel starts to yield and fail but the beam does not distort or twist sideways. Beams can also fail in buckling where they just twist and distort and collapse suddenly. Often you find buckling (Mb) is the governing criteria. We call this (Mb) the buckling capacity of the beam. Long beams buckle easily so what we do is to fix floor joists, floors or other beams to them to prevent them from distorting / twisting / moving sideways and thus we increase the buckling capacity as we shorten what is called the effective length.. that is simplistically the distance between restraint positions. If we do this well we can in cases increase the buckling capacity up to the Mc capacity and thus get most bang for our buck.

 

Lets start with beam 8 and lets assume there is not much restraint from the floors as the joists span beam 9 to 7a. The SE may be using quite a stiff connection from beam 9 to 8 to stop the twisting / provide torsional / twisting restraint to beam 8 thus increasing it's Mb (buckling capacity) significantly. If you don't do this then often you need a heavier and deeper beam. They may also be using beam 12 to further reduce the effective length of beam 8.

 

As you come up the stairs on your left hand side there is the stringer with spindles above and behind the stringer there is a space before you seem to find the first potential support. It actually looks like the end of beam 11 is supported by beam 7a. Thus beam 11 spans from 7a to beam 10.. it is beam 10 that is holding up one end of beam 11, 7a the other.

 

Now for beam 10 to hold up the end of beam 11 it needs to act as a cantilever off beam 8, but if beam 9 was not there then beam 8 would just twist and it would fall down. I think the SE has designed a very stiff connection between beam 10 & 8 and 8 & 9 so that 9 & 10 act as a continuous beam, supported at one end by the outside wall and by beam 8 at the joint. Lastly you also find that where beam 9 rests on the wall the SE has made sure there is enough back weight to stop this end of beam 9 lifting upwards.. like ballast in a boat.

 

That looks like one possible hypothesis but a caveat is that we have not seen all the info, support detail and the global structural design.

 

Lastly the diagonal bracing. I have touched on a few but not all the facets of this but you can see that the steels will be doing a lot more than just carrying the basic loads. Everything will be wanting to twist, bolted joints will slip here and there so I think the SE has introduced the diagonal bracing to stiffen things up. Also the diagonal bracing may be providing global stability to resist wind loading.

 

In summary don't remove beam 10 or any other for that matter without asking your SE! Also don't let your fabricator / metal worker change the SE's connection design in any way without asking.

 

If you have read this far then thanks.

 

Gus

 

 

Thanks @Gus Potter. I think what you are saying is that this is all a very deliberate design that can’t be changed? At least not easily!

 

[Gus Potter]

Hiya.

 

Yes I think your SE has put a bit of thought into it.

 

Can it be changed?  On the face of it you would move beam 9 to line up with beam 12 and that would open up the stair well. But the load from beams 9 & 10 would move from roughly the 1/3 point of beam 8 to its mid span so the bending forces not least in beam 8 may increase, I'm not sure though how much they may increase if that much as you will have to support less floor area. I can't give you a definitive answer as I don't have all the info.. but ask your SE the question as it may be simple to change. They may be a bit peeved as I think they will have put a good bit of effort into this.. so you may need to part with some cash.

 

But if you don't need the floor space the extra light may offset any aditional SE fee. But perversly if you are going to sell the house on the every sq metre of floor could count.

 

 

 

 

[Adsibob]

3 minutes ago, Gus Potter said:

Hiya.

 

Yes I think your SE has put a bit of thought into it.

 

Can it be changed?  On the face of it you would move beam 9 to line up with beam 12 and that would open up the stair well. But the load from beams 9 & 10 would move from roughly the 1/3 point of beam 8 to its mid span so the bending forces not least in beam 8 may increase, I'm not sure though how much they may increase if that much as you will have to support less floor area. I can't give you a definitive answer as I don't have all the info.. but ask your SE the question as it may be simple to change. They may be a bit peeved as I think they will have put a good bit of effort into this.. so you may need to part with some cash.

 

But if you don't need the floor space the extra light may offset any aditional SE fee. But perversly if you are going to sell the house on the every sq metre of floor could count.

 

 

 

 

 

thanks. I think that at this rate the only person who will sell my house is my trustee in bankruptcy!

[Gone West]

We had a deep bore soakaway drilled that went down 47m through various layers of material that were water bearing until it hit chalk and even that was water bearing. Needless to say we had to think of an alternative but on the positive side we had a borehole that produced plenty of water that we used for watering the garden.

[SteamyTea]

20 minutes ago, Gone West said:

Needless to say we had to think of an alternative

Water Source Heat Pump.

[saveasteading]

14 hours ago, PeterW said:

Assuming an existing building was square and level

It is shocking how un-level and un-square many buildings are.

Worst example I found was an indoor tennis court in a posh school that sloped 100mm from one side to the other (Don't tell anyone said the client)

And I worked briefly for a small builder who asked me to check why the bricklayer was having problems..(they had a dumpy level but obv couldn't use it). I found that the brick walls were being built in a spiral, ever upwards.

 

Very few builders or professionals can do basic setting out or geometry, and depend on machines too much.... and assume all is ok.

Assume nothing. Check by eye, check with a quality tape, check square  using diagonal distances , use a golf  ball on the floor slab. 

[SteamyTea]

4 hours ago, saveasteading said:

Worst example I found was an indoor tennis court in a posh school that sloped 100mm from one side to the other (Don't tell anyone said the client)

Wycombe Wanders always had a home advantage because of the pitch slope.  11 foot.

All changed now they have moved sites.

https://en.wikipedia.org/wiki/Loakes_Park

 

 

Edited March 14, 2022 by SteamyTea

[Bitpipe]

Hmm,

 

1) not checking that the requested warranty for the render system was actioned which may have prevented the failure (due to a, now withdrawn, carrier board) and/or would have given us more leverage with the render manufacturer to remedy

2) not accepting the initial cash settlement from the render contractor and spending 6 months trying to get the latent defect warranty to cover it during which time the contractor ceased trading (and generally not being more on the ball to get it sorted from day one).

3) ordering a £5k front door without double checking the ratio of door and glass and not getting what we though we had ordered. Was able to live with that one though as at least the frame was the correct size!

4) not supervising the last of the basement backfill - crew obviously reverted to using poorly compacted spoil not stone (as specced and paid for) and that area has now settled making the patio decidedly wonky.

5) not checking where the fixings for the bathroom vanity sinks were (clue, the cupboard, not the sink) and smugly ensuring that there were noggins in place that turned out to be 100mm too high.

 

However as complete amateurs we got way more right than we got wrong and prevented many other mistakes along the way, some at the very last minute!

[saveasteading]

9 minutes ago, Bitpipe said:

during which time the contractor ceased trading

That was probably happening at the time anyway, and the money would not have reached you.

 

9 minutes ago, Bitpipe said:

not supervising the last of the basement backfill

 

 

You supervised everything else and it was good?

 

Well done.

[Pocster]

I have nothing to add to this thread 🙄

[saveasteading]

 On my private builds?   There will always be unknowns in a refurb, so nothing to make me hurt.

 

On commercial projects:

1. Doing a trial hole which showed topsoil, a little fill, then solid clay and then designing  300m2 of building with conventional footings.

While digging the footings the bucket went through into peat. The clay was a compacted capping.

Had to very quickly redesign with piles and beams at our own expense.

Lost 2 weeks and a few £k and could have been so much worse.

 

2. Is it a mistake if you spot it first and correct it?

Woke up one morning long ago, knowing my setting out of the day before was wrong.

Asked the boss for the landrover and chainboy, before coffee and prepping for the day.

Went to the spot and adjusted the trunk road alignment to point at where the bridge would be.

Back to the site office, Boss said 'everything ok? and never asked me what it was about ....sound man.

Not that I would have minded saying, but he didn't want to know.

Moral...dreams can be very constructive.

 

3. Another issue setting out a big culvert, using a theodolite, over an obstruction. I used a spirit level as a line, but used the wrong side of it.

Told the GF that the foundations were in wrong. How did it happen? Fair enough! Any easy way to rebuild it?...yes I gave him a method,

No more said by him or the big boss, or anyone as I think no-one was told.

 

That has lived with me as how problems are handled....everyone makes mistakes, better to know about it and sort it, and no point scoring or shouting.