Teaky's attic

[teaky]

Soil vent pipe altered, extended and reconnected.  Rear face of roof re-felted, re-battened and tiles replaced.  Three of the four holes for the steel beams bricked up and made good.  Timber plates bolted to top of steel beams.  Short posts added to support new rafters where they pass over the steel beams (I wonder if they used enough glue?).

 

 

The builders won't be here tomorrow as they are playing in a once-a-year golf match for charity.  I can hardly complain since it is for a worthy cause.

 

Don't go thinking you're going to be spared a day of these exciting updates, I'm sure I'll be able to find something to post. 

 

Edited August 11, 2022 by teaky
Re-adding photos.

[Stubby47]

Will the new floorboard joists sit on top of the steel beams ?

 

If so, that's a fair sized gap between the new floor and the ceiling below. Will any of it be accessible?

[teaky]

Will the new floorboard joists sit on top of the steel beams ?

 

If so, that's a fair sized gap between the new floor and the ceiling below. Will any of it be accessible?

The floor joists will sit on the bottom plate of the steel beams.  So that's just above the insulation at the bottom of the photo above Stubby.

 

As you look at the steel beam the distance from the front edge to the large central, vertical web is just over 100mm so that gives a good bearing for each end of the floor joists.  The floor joists are 200mm x 75mm and make the rafters look small.  They will be at 400mm centres but that means there will only be an empty space between them of 325mm and there will be 100mm depth of 'wool' loft insulation between them to comply with fire regs.

 

The steel beams and wooden posts on top of them will be insulated and covered over to form the side walls of the new room.  This won't give very tall sides but I chose to have it this way to maximise the width of the room.  A perfectly valid approach would have been to have the taller side walls with the steels closer together and thereby gain a little extra height because slightly smaller floor joists could have been used due to the smaller span.  It's all swings and roundabouts.

[Stubby47]

Ah, that makes sense now.

 

The house will benefit from the extra layer of insulation, but will there be enough under the roof to maintain a useable temperature during the winter ?

 

I ask as my loft is boarded out, but is freezing in winter ( and conversely too warm in summer ). There is no insulation under the tiles, but I 'm reluctant to add any for fear of introducing a moisture trap and thus damaging the rafters.

Edited October 27, 2017 by Stubby47

[teaky]

The final roof structure will be: tiles, felt, 50mm air gap, 100mm PIR insulation between the rafters, 40mm PIR under the rafters, 12.5mm plasterboard and a few mm of plaster.  This will meet the current building regulations.

 

I know from converting the garage a few years ago that it doesn't take much insulation to keep things nice and snug.  Eight teenagers in there on a cold winter's evening produces so much hot air that the heating doesn't need to be on.  (N.B. I am not recommending teenagers as a form of heating.  They're much too noisy and the fuel input is too high.)

 

If you are thinking of improving your current set up Stu then anything you add between the rafters will be an improvement even if you can only get, say, 50mm in there.  Just make sure there is an air space between the insulation and the felt and that this space has decent air flow.  As well as the 50mm gap on mine I will also be adding additional ventilation near the ridge and fitting some vents in the soffits.  (See earlier post.)

Edited October 27, 2017 by teaky

[Stubby47]

Thanks Rob - it's the 50mm air gap that's important then.  I should add some insulation - there is enough natural ventilation already (as we get birds in occasionally).

[teaky]

Thanks Rob - it's the 50mm air gap that's important then.  I should add some insulation - there is enough natural ventilation already (as we get birds in occasionally).

Perhaps that's a little too much ventilation then?

 

The important thing is to have a flow of air which allows any moisture laden air to escape without condensation being created.  At the same time, you don't want a howling gale blowing through because that draws away heat.

[cb900f]

Rob,

 

I take it from the above that you haven't got to lay 25mm chicken mesh between the new joists to support the 100 mm insulation ? I have had a new higher roof built with 4 dormer windows fitted. The building regs guy has deemed that it is now a habitable room ( I guess it was the windows that gave it away) and has insisted that I use the chicken mesh, it is a real pain in the backside to fit. I also have got to fit 11 fire doors throughout the house and 3 smoke alarms on the 3 levels. All this money and effort for a model railway, I must be mad but as you say it all adds to the house when it comes to moving on.

 

Pete

[bgman]

Rob,

 The building regs guy has deemed that it is now a habitable room ( I guess it was the windows that gave it away) and has insisted that I use the chicken mesh, it is a real pain in the backside to fit. I also have got to fit 11 fire doors throughout the house and 3 smoke alarms on the 3 levels. 

 

Pete

 

Worth the effort when a life or lives can be at risk, and please don't forget that the Approved Documents being administered by Building Control only require min. standards to be applied, and those are for everyones safety. 

That said, enjoy the room for whatever purpose it is intended to be used as in the knowledge that the Building Control officer has you and your families best interest at heart.

 

( If you think the above may be a biased view you would be correct......from a happily retired BCO and railway modeller )

[teaky]

Rob,

 

I take it from the above that you haven't got to lay 25mm chicken mesh between the new joists to support the 100 mm insulation ? I have had a new higher roof built with 4 dormer windows fitted. The building regs guy has deemed that it is now a habitable room ( I guess it was the windows that gave it away) and has insisted that I use the chicken mesh, it is a real pain in the backside to fit. I also have got to fit 11 fire doors throughout the house and 3 smoke alarms on the 3 levels. All this money and effort for a model railway, I must be mad but as you say it all adds to the house when it comes to moving on.

 

Pete

Yep, this is no different Pete, but rather than lay the mesh after the floor joists are in I chose to fix it to the existing ceiling joists.  See posts 27 to 30.  This wouldn't be an option for anyone fitting under slung floor joists but in my case the bottom of the new floor joists will be above the ceiling joists.

 

I appreciate you asking though.  For the inexperienced like me it is easy to miss things.

 

If you don't have one already I recommend buying an electric stapler.  (A bit like a poor man's nail gun.)  They really help.

 

Did you not have smoke alarms already?  Our house has them in the hall and on the landing and all I've had to do is connect in to the landing one using some 3-core and earth cable which will run up to the new alarm in the loft.

 

Blimey, 11 fire doors.  I hope your door frames are straighter than mine.  I have done seven so far with just one door left to do and some of them have been a real faff with lots of planing, sanding and adjusting.

[teaky]

btw There's a small bonus with fire doors.  Our house is significantly quieter (when the builders aren't here).  Although the effect may be greater because the old doors were the hollow type.

[cb900f]

Worth the effort when a life or lives can be at risk, and please don't forget that the Approved Documents being administered by Building Control only require min. standards to be applied, and those are for everyones safety. 

That said, enjoy the room for whatever purpose it is intended to be used as in the knowledge that the Building Control officer has you and your families best interest at heart.

 

( If you think the above may be a biased view you would be correct......from a happily retired BCO and railway modeller )

Yes I know he has my best interests at heart, he is quite a decent chap really. It's just that the chicken mesh had to cover an area 36ft x 15ft, took me about a week to complete.

 

Pete

[cb900f]

btw There's a small bonus with fire doors.  Our house is significantly quieter (when the builders aren't here).  Although the effect may be greater because the old doors were the hollow type.

The wife isn't too happy as the present doors are inset with glass panels that let a lot of light into the hallway. She certainly will not accept glass doors with wire mesh through the glass.

 

Pete

[Richard_A]

You can get fire rated glass. My old boss had to use it on a couple of houses we built, all he ever said was " break them,you buy them " so I guess it expensive!

[St Enodoc]

You can get fire rated glass. My old boss had to use it on a couple of houses we built, all he ever said was " break them,you buy them " so I guess it expensive!

Fire-rated glass is commonplace down here.The boundary of a bushfire zone runs through the middle of my railway room - although as I'm not sure that the fire front will know exactly where to stop I had the whole structure but to comply with the bushfire regs - including the windows in the workshop area.

[teaky]

Well that's the front of the house fitted with eaves vents.  There are certainly a lot of spider's webs.  No doubt inhabited by upset spiders since the webs are now very visible with their uPVC dust dressing.

 

I thought this was going to take longer but the most time consuming aspect turned out to be getting the uPVC discs out of the hole cutter.  I might have to devise some kind of tool before I tackle the back.  Top tip: I made a simple jig for marking the hole positions from an off cut of timber with lines marked on it which enabled me to mark the centre points of the holes a consistent distance from the front edge of the eaves and at the correct intervals (200mm in this case).  The scaffolding has a row of cross braces that exactly match those on the main top platform so I was able to remove a couple of boards down by just over 0.5m and lie on my back to drill the underside of the eaves.

 

There are still two left to do which I'll need to do from a ladder after the scaffolding, which was in the way, has been removed.

 

I'm not bothering with photos.  I posted a picture of the circular vents a while ago and they don't look significantly different once installed.  I might take a snap once the scaffolding is out of the way.

 

Time for lunch.

[Stubby47]

Drill a small hole somewhere within the circumference of the disc to be cut out. Bend a thin piece of wire so it has a short length folded back along the length.

Cut the disc, then insert the folded wire through the previously drilled hole, then pull the disc out of the cutter.

[teaky]

Drill a small hole somewhere within the circumference of the disc to be cut out. Bend a thin piece of wire so it has a short length folded back along the length.

Cut the disc, then insert the folded wire through the previously drilled hole, then pull the disc out of the cutter.

There may be some mileage in that idea.  Thanks Stu.

 

The discs are too tight a fit to just pull out but I might be able to use the wire to rotate the disc and reverse it up the central drill bit.

 

I've only used hole cutters for walls, plasterboard ceilings and kitchen units before and not encountered this problem, so it took me by surprise.  I'll have to give it further thought whilst I get on with something else.

[chris p bacon]

When I cut UPVC I tend to 'rotate*' the hole cutter as it's cutting so that it makes the disc inside the core cutter a looser fit.

 

Depends how much slack you've got between the cutter hole and vent.

 

 

 

* or wiggle it about.

Edited October 28, 2017 by chris p bacon

[teaky]

When I cut UPVC I tend to 'rotate*' the hole cutter as it's cutting so that it makes the disc inside the core cutter a looser fit.

 

Depends how much slack you've got between the cutter hole and vent.

 

 

 

* or wiggle it about.

I'll have to opt for wiggle in most cases due to the proximity of wall and scaffolding but I'll give that a go.  I can see how that would work.

[Tref]

Some of the hole saws have a little slot in them, if it does, an Allen key is your friend for pushing out the plug.

 

Tref.

[teaky]

There are four slots but it was still a pain.  I was using a bent nail but the Allen key is a good idea as it would provide better leverage.  Thanks Tref.

[teaky]

It's all in the wiggle!  Thanks for the tip Dave.

 

I ascended the scaffolding prepared with additional kit (Allen key, extra drill bit) but in the end giving the drill a little wiggle as it went through and applying less upward pressure did the trick for the majority of the holes/discs.

 

I have a three or four vents to fit once the scaffolding is out of the way but that's more-or-less job done on the eaves vents. 

[teaky]

I know you really want to see what the soffit vents look like in situ, so here you go. 

 

 

Edited August 11, 2022 by teaky
Re-adding photos.

[chris p bacon]

I run a string line from one side to the other so they're all in line.....just saying...