Inception, Initiation and Indication of Insulation Installation Information

It's getting to that stage of the job where what would normally be large stand alone jobs have to be split into smaller parts to allow related works to be progressed.  In this case, i need to complete the construction of the party wall to be able to construct the en-suite partition, which in turn is required to allow the electrician to finish his first fixing of cable runs.  Normally the velux windows would have been fitted prior to the insulation being fitted to the roof, however, poor weather and limited daylight hours are making this difficult, so i'm pressing ahead with the fitting of insulation in particular areas.

Budget management is crucial and an opportunity arose to purchase all my insulation in one go at a very good bulk price.  The advantage of this is that I will have all the insulation to hand as each part of the job progresses.  The dis-advantage (for some) is the need to store all the materials. Fortunately i have sufficient storage space.

A 'local' company (20 miles away), Malcolm Insulation, was able to provide all of the insulation i needed.  The 80mm and 40mm sheets for the roof and oxter walls and the 145mm slab for the oxter and party walls.  The approved drawings recommended using Kingspan, however Malcolm Insulation supply Ballytherm boards and they were able to confirm that the U and R values provided the same level of thermal insulation as Kingspan but for half the cost.  They were even able to deliver within 24hrs of my order. Can't argue with that!

Quite a pile of insulation.  Fortunately, the garage was able to hold it all.

As you will recall from the previous post, the party wall partition was to be insulated on the back side, with a 25mm gap to be maintained from the party wall.  The 40mm boards were secured in place using 'No More Nails' and as per the picture below, the 25mm gap was maintained.  80mm insulation boards were also fitted to the roof rafters.

25mm air gap between party wall and partition

The 80mm insulation boards were cut and push-fitted between the rafters on the roof side.  A 50mm air gap between the underside of the sarking and the insulation board was maintained by the fitting of small 50mm fillets.

Once the No More Nails had set and the insulation boards were secure, the 145mm insulation slabs were cut and fitted into the party wall partition.

So there we go, now you have information on the installation of insulation and an indication of it's initiation and inception. 

Party Like It's 1999 (2015 edition)

A Party wall is a main separating wall between buildings.  Responsibility for the wall is normally shared between the owners of the buildings (the parties).  In this case the Party wall is the wall which separates the two homes within this semi-detached building.

The last time i worked full-time as a joiner was 1999 and whilst the skills and techniques remain the same, the building regulations of 2015 have changed a wee bit.

The party wall was parged (coated in cement render) at the start of the year.

The building regulations require the construction of a 150mm x 50mm partition at the party wall.  This partition, like the oxter walls, will need to be insulated by the fitting of 145mm insulation batts and 40mm Kingspan/Celotex insulation board.  In the case of the party wall partition the 40mm insulation board is to be fitted on the back side of the partition and i've left space in the partition (the missing dwangs) for this to be slid into place later in the project.  It saves a £50 delivery charge if i make one large order of insulation with free delivery rather than 1 small and 1 large order.

One of the other changes in building regulations is that a minimum gap of 25mm must be kept between the back edge of the finished partition and the party wall to ensure adequate ventilation within the loft space around the whole 'box' of the conversion.  In this case the back edge of the partition will be the insulation board and the bare timber partition had to be built 65mm away from the wall to account for the 40mm insulation board.

The Party wall partition requires to be finished with two sheets of 12.5mm plasterboard which are then to be fully plastered, so overall the finished partition will be approx.. 220mm broad.  Hopefully that should provide adequate thermal and acoustic insulation between my neighbours and I. 

Heatseeker

Now that all the joists are in place it's time for the 1st round of insulation fitting

In the eaves, behind the steel beams, some of the original loft insulation was re-laid in between the joists.  Prior to re-laying I had to fit an eaves ventilation roll.  This is a corrugated plastic roll which ensures that there is a decent gap for airflow into and around the remaining loft space from the external eaves vents.

Sometimes people fit loft insulation and stuff it right into the eaves restricting air circulation and creating good conditions for condensation build up, fungal growth and potentially dry rot.  

I laid a second layer of insulation across the joists on top of the insulation laid between the joists to give at least a 300mm layer of insulation within the area of the loft which will not form part of the new room.  

One of the first jobs to be done way back at the start was to lift the existing insulation and i was surprised to find a layer of loose cork insulation under the original loft flooring.  A quick check on t'internet showed that loose cork had the same insulation qualities as approx 150mm of modern insulation quilt, so i set it aside and then when the time came I just poured it in between the joists of the floor of the new room before laying 100mm of insulation quilt on top. Not only will this provide good thermal insulation it should also improve acoustic insulation between the new room and the rooms below.

Dwanging, hope you like dwanging too.

With the steel beams fitted and secured in place, it was now time to fit the structural joists which would form the new floor level and would be hung from steel beams using the twisted hanging straps.  The picture above shows the flitch beam in place and hung from the steel.  The flitch beam will help provide structural support for the stairwell opening.

This is the future stairwell opening.  All joist ends are hung from joist hangars and the two joist hangers at the far side are bolted through the joist into the chimney breast wall.  The flitch beam is the large double joist nearest to us in this picture.  The existing 6"x 2" joists have simply been cut and are sitting in place until the time comes for the stairwell opening to be cut.  The opening will be circular to fit the shape of the planned spiral staircase.

As you can see, the building up of the existing 6" x 2" joists to create 9"x 2" sized timbers which were then sandwiched between the 9"x 2" joists has created very substantial timbers which span the length of the loft and are hung under the steel.  Fitting all of this took twice as long as i had initially thought (and was twice as dear) and as a result I'm now about 1 month behind schedule (and budget).

Once the joists were fitted and hung from the steel the entire floor had to be dwanged out.  Lots of little 9"x 2" dwangs all needing to be cut to size, knocked into place and nailed.  My knees don't like dwanging!

As well as dwanging the joists the oxter supports required to be fitted in their final place.  The supports were moved back approximately 8" from their original place on each of the 3 sides of the loft and this should create a room which is 5m x 5.5, (incl. the en-suite).  The supports were bolted through the roof trusses with toothed connector plates in between.

All of the structural joists were hung from the steel, with the twisted hanging straps used on both sides of the steel beams and nailed in place with twisted square nails.  As per the structural engineers specification, the steel beams each had to have two restraint brackets fitted which prevents rotational movement of the beams.

After all this was done the work was inspected by the Building Standards Officer of the Council and i'm pleased to say that it was given the seal of approval.  Onwards and upwards.

Loft Conversion - Steely Done

With the steel now lifted into the loft it was time to start the job of fitting the beams in place at each side of the building.

These are the steel shoes which are designed to act as a support bracket for the steel beams and to stop them twisting or rolling over onto their side.  They were manufactured by Gilchrist Steels of Glasgow on the same order as the steel beams.

The steel shoes were bolted into the brick party wall using M12 threaded rod and bolts rather than expansive rawlbolts.  The threaded rod was fixed in place using anchorset and left overnight to cure, the next day the shoes were bolted onto the road and tightened up.  I was surprised at just how secure the anchorset was, with absolutely no movement in the rod as i tightened the bolts.

I slid the steel beams into place myself and whilst it was a heavy manual job it was something which was fairly straightforward.  Once the beams were positioned, levelled and lined up they were bolted together at the spliced joint using the plates and M20 bolts specified by the structural engineer.

Once both steel beams were fitted in place, each side of the web of the beams had to be filled with 8"x2" timbers which had to be bolted through the web at staggered intervals.  These timbers will provide a fixing for the C24 structural joists which will be fitted under the steel beams and hung using 400mm steel joist hangers.

and here's the steel beams with timber infill finally fitted in place.  Phew! 

Loft Conversion - Gies a lift mate

The time has finally arrived for the steel to be lifted into the loft space.  This is certainly one job that couldn't be done myself and thankfully i have really willing and helpful family and fantastic friends who all came along on the day to help out.  Most importantly my friend brought his hiab truck along to do the big lifts.

You may recall from an earlier post that there were two 7m long steel beams and a 6m long flitch beam to be fitted into the loft.  The steel beams were split in to 1/3rd and 2/3rd sections which will be spliced together in the loft.  Each of the long sections of steel weigh 205Kg, the smaller 1/3rd sections weigh 100Kg each and the flitch beam weighs approximately 250kg.  These, combined with 10 of the 6m long C24 joists which needed to be lifted in meant that in total we need to lift approximately 1 tonne of materials into the loft space.

Thank heavens we had a crane! 

Before the steel was lifted into the loft the padstones and bearing lintels were fitted into place.  These will take the weight of the steel beams and the loft floor which will be hung from steel beams.  This will mean that the weight will be transferred down the walls and onto the foundation of the building.  At the other end the steel beams will rest on a larger lintel section and steel shoe which will be bolted to the party wall.  Again this is designed to transfer all the weight down to the foundations.

The 'easiest' way to get the steel, flitch beam and joists into the loft space was by opening up the roof, lifting each item up and sliding it into the loft space.  We used the winch in the loft space and a steel roller plate to make it a bit easier to pull stuff inside.

From the inside

This is the flitch beam being slid into the loft space through the opening.  The crane took most of the weight and there was two people inside pulling the stuff in.  Once over half of the beam was inside the loft the chain was taken off and the winch inside the loft was used to help pull the beam inside.

I love how this picture makes it look as if i simply slid the steel beam into the loft space.  However, the reality was quite different and it was a heavy going 4 hour long job just to get it all up and in, with an hour and half each side of that to open/close the roof and erect/dismantle the scaffold.  If it hadn't have been for my mate and his crane this job wouldn't be happening and if it hadn't been for my brother, father-in-law and a few other friends the steel wouldn't have made it into the loft.  The exact opposite of Dae It Yersel :-) 

The short section of steel is now in place, resting on the lintel bearer.  The next steps are to line and level everything up, fit the steel shoe then lift the larger section of steel into place and bolt it all together.

Thank heavens for family and great friends.

The best winch I've ever had

For the next job I had to fit a 1.5m long K9 lintel weighing approx. 125Kg in the loft to provide some support for the steel beams which are hopefully going in this week.  The only problem was that the lintel had to be lifted 2.5m up into the loft space!  

To get the lintel up onto the top landing i simply strapped it onto a barrow and wheeled/bumped it up the stairs.  Seemples! 

I had previously lifted a smaller lintel up into the loft by sliding it up the planks of wood next to the ladder, however, this wasn't an option for the larger 125Kg lintel.

and here is the lintel in it's final place, resting on padstones at either end.  The steel support bracket/shoe for the steel beams is just sitting in place prior to being measured, marked and bolted to the party wall.

But how did you get the lintel up there i hear you ask.............

.......I used this electric winch, which i borrowed from my brother-in-law (but don't tell him, he doesn't know i borrowed it yet).  I bolted it to its swing arm and simply sat it across the newly fitted C16 collars above the loft opening.  After that i just lowered it, hooked it onto the barrow and pulled the barrow and lintel up the planks of wood.

Hey presto!  One lintel (and barrow) winched up into the loft space.

I wonder if this is how Stanley Kubrick lifted the monolith into place.





p.s. for my non-Scottish readers - a winch is another name for a kiss.

Loft Conversion - Collared

To provide a decent amount of headroom in the new bedroom the collars which spanned across the rafter at approximately 1.9m were moved upwards to 2.4m but renewed in C16 structural timbers 145mm x 47mm, bolted through with M12 Grade 8.8 bolts and toothed plate connectors.

This is the  1.9m height of the collars as the roof trusses were originally constructed.

The new C16 collars were cut and fitted in place temporarily and then string lined, levelled and marked to ensure a level fitting across the width and length of what will be the new ceiling.

The existing collars remained in place whilst the new ones were fitted.  This made the fitting a wee bit awkward but it meant there was no movement in the roof trusses at all.

Once the new collars were lined up and marked, 13mm holes were bored through them and the existing trusses,toothed plate connectors were fitted between the timbers and then the M12 bolts were used to bolt the timbers together.

Once sufficient torque had been applied to the bolts and the toothed connectors were bitten into the timbers the old collars were removed and set aside for reuse elsewhere in the conversion.

The extra 500mm in height makes a considerable difference to the feeling of spaciousness already.

Loft Conversion - Deforestation in action

This is the first delivery of timber and whilst they look like pretty substantial timbers, these are just the 9" x 2" packers required to pack up and out the existing 6" x 2" joists.  These 'packers' will then be sandwiched in between structural 9" x 2" C24 timbers which will be hung from the steel beams.  Yup, you guessed it, the structural engineer strikes again!

The yellow tinged timbers are the C24 structural timbers specified by the structural engineer.  When assmbled these timbers will create thirteen 9" x 8" joists.  To put this in context, the first floor of my house is supported by single 8" x 2" joists spliced over a supporting wall, much in the way that the existing loft joists are.

This is the detail at the splice joint of the existing timbers.  The 9" x 2" extends the spliced joist 300mm past the line of where the steel beam will sit.  84mm high timbers will site on top of the existing joist to create a 9" x 4" sized joist.  The C24 timber will then sit either side of this and be coach bolted through at staggered centres to create a 9" x 8" sized joist.

This is the view from the other side of the joists

Loft Conversion - Steel yourself for this nonsense

Here are the steels which the structural engineer has insisted is the only way to support the additional en-suite bedroom in the loft space.  These are required in addition to the 'quadrupled' up 9"x2" joists and the flitch beam.

and here's a close up of the 6.8metre long x 254mm x 146mm x 43Kg universal beams which i need to crane into my loft to hang the 9"x2" C24 joists from.  They have a spliced joint at 2/3rd section and when bolted together each of these beams will weigh 300kg (47 stone).  In my opinion this is complete overkill and could have been avoided by the use of alternative glue-lam beams or other modern, timber composite alternatives to steel. So, here we are already £4k over budget.

This is the flitch beam which I had to construct to satisfy yet another requirement of the structural engineer.  The flitch beam comprises of a 6m long x 200mm high x 13mm thick steel plate sandwiched between two 220mm x 50mm C24 structural beams the same length. The flitch beam will sit at a 90 degree angle to the steel beam around the edge of the stairwell opening and will be suspended from the steel beam by anchor ties.

The assembly is held together by 130mm grade 8.8 x M12 bolts placed at 200mm staggered centres with single sided toothed connecters either side of the steel plate which bite into the timber.  I estimate that this weighs approximately 120Kg (19 stone) and because of the length and weight this will need to be craned straight into the loft along with the steel.

Structural engineer - bolt!