Builder starting small extension, will I regret it

[Oldman]

The drainage run is following the new walls of the building so L shaped for stormwater. So from far end its Trapped gully-110mm pipe-sweep tee picks up the french drain- 90 deg bend-tee for 2 x Aco sections via a trap-more 110mm pipe and into manhole (combined service)
The toilet pipework is a vent stack with hopefully later today an upstairs toilet takoff, other bathroom wastes into it, down to ground level where it enters the manhole too. downstairs loo also enters the same manhole so its a bit busy in there.
There is nowhere to bung the french drain without a redesign.

The brickies line is a red herring, end of day and its been moved up some to clear the last course.

The steel section on the corner is in fact a bit of my Unistrut so bears no relationship to a guage rod other than the fact its not bent and is being used to butt the bricks up against :wink: and give somewhere for the string line to clip onto.

http://www.unistrut.co.uk/index.php?par ... %20Channel

I just finished a temporary replumb of the bathroom waste, what a pita that was with old 1 1/4" and 1 1/2" married up to 32 & 40mm, still its done and poking out the wall now waiting for a stack to put it into, he did say he would be back to build the stack today, hope so as the family need showers.
Bricky is hating the weather, must be near 30 deg here, not so good for building walls in I am told.

 

[trousers]

Not a gauge rod, it's a diy version of bricklayers corner profiles.

perps are rarely fully filled

Thats because a lot of bricklayers are lazy. They butter the face edge (only) of the next bricks perp with what they scrape off from the excess bed cement from the previously laid brick, which saves them having to bend down again to butter the perp with fresh cement from the spot board. Therefore quicker = more laid in a day.
Doesn't make it good practise tho'.
In fact in an exposed location it could well result in rainwater getting through the perp to the inside face of the brick. And in an internal partition wall will result in poor sound attenuation - and a failed attenution
test if they ever bothered to do one :roll: , esp in a party wall.
It's all about attention to detail really.
Every tradesman works to their own standard, just some have higher standards than others.

 

[jasonB]

I hadn't looked that closely at the holes but as you say they have no relation to teh coursing, looks like a bit of Unistrut to me.

Jason

 

[Dibs-h]

I hadn't looked that closely at the holes but as you say they have no relation to teh coursing, looks like a bit of Unistrut to me.

Jason

Could one use angle section as corner profiles - say s\s if corrosion is an issue? Say something at least 2"x2".

 

[Oldman]

Todays progress for your perusal.

New window to go in there when it arrives. Dont ever order a upvc window by phone, gave the sizes and they made it different, by the time I got the written confirmation it was too late to adjust the size so now its a case of adjust the brickwork to suit....grrrr...

Very "busy" in the corner by the downstairs loo with a vent stack very close to the window edge (once its vertical and fixed) downpipe still to be adjusted :wink: Got the shower/basin waste into the stack for now anyway so we can shower tonight.

This big window is coming out, pity I dont have a use for it. The roof cladding is all going too as the new and old roof will be joined and the fall changed to away from the house.
The old black soil pipe is all going soon I hope.

 

[Oldman]

Another fine day and lots done by the bricky.

He says it will be tidied and siliconed down the join between the new and old brickwork in this busy corner.
Dont take notice of the old brickwork, it was a pigs ear when done before I bought the house and I have been threatening to have it rendered over ever since.

Blockwork nearly finished too.

Hope I didn't go for too small a window, once the wall on the right is gone it should get more light in there.

Tomorrow is lintel over window and some cut blockwork, start to remove the cladding on the old extension to see whats hiding under there. Again that was done before I moved here so I dont have a clear picture of what they will find.
The Aco drains should also be going in tomorrow and the damaged and removed paving replaced.

 

[Oldman]

OK so the rain held off and it was yet again a hot sunny day.

The plastic boxing over the old extension came off, what a strange affair that was, underneath it was a conventional gutter and felting edge.

Then a quick rip off on the front corner to see what was there reveled what looks like a wall plate with 8" timber beam with would you believe 4" x 2" close boarded together all over the roof which is I guess covered in ply then felted. We shall see on Monday when I think they may be stripping the roof.

Good news for me if it is covered in 4x2 as its now well seasoned and will make good timber for a shed rebuild I have in mind.

Once they had figured out the old plate levels the new walls were taken up so hopefully it all ends up the same level when the joists, ply then 90mm celotex sheets then ply again gets added next week.

Lintel is in over the window and the cut blocks are on to plate height.

The broken paving got taken up today as well though I couldnt quite see the logic in that as they have plenty of other work to do before laying the originals back down. Laying the ACO drains didnt happen today either, so thats still for another day.

 

[trousers]

My money is on the boards being 4 x 1 and no ply over the top.

Any further bets? :lol:

 

[Oldman]

Nobodys betting Trousers

OK Friday has been and gone, Bricky & mate arrived before 8am today expecting all the timber for the roof to be here at 8am. Reality kicked in and it arrived at 10:30am

They cut a slot in the house wall for the main beam.

This was supposed to be tight up against the original roof but as the old roof water run off was that direction the felt and overhang stopped them getting any closer than butted against the edge of the felt as they didnt want to make the old roof not watertight by cutting it back.

Shows the concrete pad for the plate to sit on, note the blocks seem to run out below the window.

95x45mm timbers were set on top of the blockwork.
Once the 3 timbers (190mmx45mm) were in place in the slot they were drilled and bolted together, then hangers attached and the joists attached.

A bit of trimming to do later...

All was well till 2pm when the Builder turned up with a twisted ancle & told them to stop the job and come with him, seems he had another job on the go and had the roof in a state where water could enter so needed help to finish it up before it rained. :roll:

So I am left with what will very quickly become a swimming pool if it rains more than it is right now as the extension is a sealed tank atm with no roof.
The main house roof rainwater is set to run onto the old flat roof and thats got no gutter now so pretty much all that falls will be in the new extension as the old roof fall is that direction.

Here are pics of the sheets of ply & osb, firings and celotex which I was hoping would be on today, well on the new ext anyway.

Hmm...its just started raining harder, oh bother!

Looking for fine weather now until Monday or Tuesday at least.

 

[Oldman]

Going to be an awfully thick roof structure when completed, just been looking at this detail for a warm roof. Looks to add around 5" on top of the joists at the thin end of the firing & 8.5" at the Lead flashing to original house end.
Thats 16" of roof structure at maximum. Boy thats a lot.

Quote:
A warm roof has the insulation on the outside of the structure which means the roof decking is effectively inside and therefore the deck is kept warm (hence the name). Because the deck does not have two opposing temperatures, i.e. cold from outside and warm from inside the chance of condensation or damp is eliminated, Because there is no dew point at decking level this means that ventilation is not required, which in turn means that any pipework, wiring, ducting, etc is not subject to extreme temperature differences or moisture.

Going to need to figure the permitted drilling zone for that treble thickness joist too as I do need to get a bunch of cables through that.

 

[superunknown]

I am just over a year in to my house extension. I have done all the work myself except the groundworks, brickwork/blockwork and the roof timbers. I also work full time and I have to say its been killer especially the plastering, that seemed a never ending job.

We have a coat of paint on the walls and ceilings now and getting ready to second fix and start to make bathroom cabinets etc .



Good luck.

 

[Oldman]

Would anyone like to comment on the chosen direction of joists on this extension?
Seems to me as a layperson that they have run them a strange way, I would have bolted a wall plate to the main house wall and run the joists from there to over the window opening allowing the firings to then sit directly on top of the joists along the complete length.
At 4mtr the span seems still to be within the timber size chosen with 400 or 450mm spacing.
The firings will now just be in contact with the joists where they cross them at 90 deg which is what looked a bit strange to me.

 

[studders]

Would anyone like to comment on the chosen direction of joists on this extension?

The shorter span, whichever way that is, would be my choice.

 

[Oldman]

OK Studders, its as you say on the shortest span, just didnt seem logical to me that way round.

Trousers, you win, you were closer than me.
The old existing extension has 4" wide by 3" wall plates on top of the final brick course, then 2 1/4" x 7" joists with 3 3/4" x 1 1/4" boards close boarded all across the top of that.

I think some bricks may need to come out on Monday, just had a measure and the outer opening for the window frame to the underside of the lintel is a few mm under 1mtr. The window inc sill is 1mtr. Whoops!
It means a course of cut down bricks under the sill I guess. Needs a bit of clearance there to square up the window frame I think.
All this cause the window supply company didnt listen when I told them 1070mm and made it 1000mm which messed up the brick spacing.

 

[Oldman]

A bitty day today with firings and osb laid on the new roof joists. Getting the sheets up there disturbed the top row of outer bricks so bricky had to pull the row off and start again.
The trap and connecting pipework went in for the Aco drains though he was short of a connector so the Aco itself isnt in yet.
Then the rest of the day was spent cleaning up and relaying the paving around the extension plus cutting slabs to fit up to the new walls.
Bricky put the still diamond cutter through the outer walls where they are coming out and says he will do the inners once the old windows are out with a saw or bolster to save on mess.

Roofers will be on site Thursday weather permitting to lay the new felt and I got asked if I wanted solar reflecting paint or chippings on the roof, I hadnt considered paint and it seemed like a good idea reflecting the heat away and nothing for the moss to attach itself to in the winter.

The BCO turned up 11am and was on site all of 5 mins, he glanced at the roof from the ground and asked where was my ventilation going to be. I said its a warm roof...
I did ask him if he was ok with a solar paint on the finished roof, he advised against it suggesting that its only going to last 3-5yrs before needing painting again and its a very expensive product. So looks like its going to be chippings again for me.

The builders elseware again Tuesday so that gives me time to remove the existing kitchen units/sink thats against the wall thats coming out, repipe the hot and cold supplies and wastes etc so when they remove the wall I can hopefully still use the old kitchen, just with no wall behind the units.

 

[RogerS]

Progress is looking good. What happened with the DPC?

 

[Oldman]

Going on the form of my day I just typed a very long detailed reply and somehow hit a key near Z which completely cleared all I wrote! :evil:

So again... Tuesday I did all the plumbing jobs ready for the old kitchen wall to come down and fitted a new outside tap for them while they were away.

Today Wednesday they arrived and rushed into stripping my old extension roof so they could board the whole lot as one roof.

Seems the gods were not with me. The old roof had joists that were set lower in the middle to force the water to the middle of the roof area before the firings direction sent it off the side. I wanted to add timber strips to the low middle joist tops to level it up but they thought it would take too long and didnt want to do that as they needed to finish today for the roofers to start first thing Thursday.
So I got a hodge podge with the first 1/2 of the old roof shuting water away from the house as I wanted, but then the slope changes direction to push the water towards the new roof so god knows what will be the result, though they assure me all will be ok.

The ply sheets turned out to be a mistake by someone but they used them anyway, looks like shuttering ply to me. I thought roofing sheets were supposed to be wpb?
The rest is osb.

After they left I began to wonder about the insulation in the cavities and didnt see them being filled before the roof went on. I checked the side of the new ext and sure enough it was 50cm short of the top of the cavity.

The front over the window opening was hard to check as they have added a joist to the outer brick edge and there is another just next to the blocks on the inside. Lucky there was a gap where the gutter spout used to be so with a mirror on a stick I found no insulation above the lintel

To my thinking this leaves a huge cold bridge and has to be corrected, a waste of time and money putting 90mm celotex on the roof and letting all the cold in through the wall tops.

Only 2 ideas I came up with is to either remove some of the top blocks over the window to get insulation in there or maybe drill holes and foam fill with insulation?

Here is what it looked like some days ago and still would if you could see inside.

Anyone know what the noggin spacing should be on these timber joists to stop twist?
The builder wasnt going to fit any untill I asked, I thought you had to fit them or when they moved about your ceiling gets cracks?

Here are some older pics

Spacing of joists is around 450mm.

Could do with some feedback tonight so I am ready for tomorrow pls.

 

[studders]

Could do with some feedback tonight so I am ready for tomorrow pls.

Well I'm certainly no expert having only done 3 or 4 of these roofs for friends.
You are the customer and you are paying good money for this job so, if you're not happy with something it is totally irrelevant IMO that 'it has to be done today because..' that is their problem, not yours. Have you paid for WBP Ply? If so then thats what should be on there (have to say mine isn't and I've not had any problems in the last six years.) My roof only has a noggin in the centre (5.5 metre span) and there has been some twist so I should have put more in I think.
Can't really help with the missing insulation as I don't know but, it doesn't sound right to me.
If the roof doesn't shed the water as it should, and the said would, then they'll have to come back and fix it.

 

[BigShot]

From memory, 1 noggin every 3 metres is the norm. I'd check my notes but that'd mean firing up AutoCAD and I'm about to head off to bed so nothing doing. Hopefully someone will be able to confirm or refute that.

You're right about the cold bridge. Stopping the insulation short of the top of the wall is a no-no. Again I've got details lying around somewhere but I'm not sure where. (I don't usually need to design to that level of detail so I can't say for absolute certain and I seem to recall there's meant to be something to plug up the top of the wall too.)

Are the joist hangers nailed through every hole? If not, they should be. Sounds excessive but that's how they are meant to be fitted.

Drilling through beams for cables is usually done right in the middle (the top of a beam is in compression along its length, the bottom is in tension along its length, the middle should be neutral so can tolerate some drilling).

If in any doubt talk to the building inspector - the main inspector I deal with is brilliant, really helpful, and if yours is anything like him he'll be only too happy to help.

Warm roof thickness... I dunno if it's too late now, but it's possible to put some of the insulation BETWEEN the joists so the whole shooting match comes out thinner overall. I have specifications for Kingspan insulation here but things may be a tad different with Clotex. The technical department at Celotex should be able to answer any questions you have though, as should your building inspector.


As for your vanishing post... (I assume you're using a Windows or Linux PC here, I dunno what it's like on Apple machines)
If you're typing and lose the lot, try pressing Ctrl+Z. That's the keyboard shortcut for Undo and if it was all deleted with the Backspace or Del key, or all cut by pressing Ctrl+X (near Z so could be that) then pressing Ctrl+Z stands a good chance of bringing it all back.

Sorry you're having a hard time with builders. Some take pride in what they do and make sure you get a good job, others are completely feckless and shouldn't be let near someone's house.

Thankfully the guys I usually do drawings for tend not to be the useless types and actually act like they've done the job before and do it properly.

Hope this post helps you out a little bit,

Good luck with it.

 

[Oldman]

Thanks for the replies guys, not looking forward to 8am. I'm not too good at confrontations and the builders already have me marked down as a picky bugger.

From what I could find on the net so far it seems that I have a small list of items to address.

Lack of insulation at top end of cavity walls (cold bridging)
Joist hangers not nailed enough, lots of holes unused.
2 rows of noggins needed, one center and one over the wall plate
No restraint straps holding the roof down
Possible ponding on the roof, will need to hose test that once its laid.
Also probs with DPM and screed height to sort.
Much too late to add a vertical dpm where the new walls join the existing.

One thing noticed with this warm roof structure is that the facia boards are going to be really ugly, very deep. Ho hum...