iron- & stringy-bark house extension

[brynk]

well, 14 days of design, 14 more days of eagerly awaiting delivery, and 14 days of a pained & painful construction process culminated last saturday night with a deck-warming cum birthday pissup to (try and) remember

talk of the deck had been on the cards before i even came on the scene. currently coming out of winter hibernation & lookin for something to revv me back into the outside working season & after a sufficient amount of alcohol-based lubrication, we decided to 'just do it'.

initial designs varied considerably but after some consideration of external decks in the canberra region (parliament house foreshore - still looks great after two years gav) and some early pricing down at buntings had us thinking that seasoned treated pine was more expensive by metre-rate than unseasoned hardwoods and due to its lower strength, more of it would be required with shorter spans, which meant more holes, more concrete, more bolts, etcet - we started looking to mills to supply hardwoods that fell into the class 1 / class 2 external, fully-exposed category.

after much searching & a bit of luck we discovered a pallet manufacturer who has ties to a mill in the region. they wound up supplying us with the structural timber & also the decking which was left overs from an earlier order & came at the right price. as fate would have it, the mill had stacks of red ironbark needing to be processed - we finalised our cutting list and placed the order.

a strenuous two-week wait with rain slowing deliveries from the mill, during which time i set about discovering just where all the pipes were at the back of the house (if there's services to be found then i'm your man!), the timber finally arrived & construction of the structure began in earnest...

as soon as i had carried it all down from the top of the driveway i sealed the end-grains of each stick with candle-wax to prevent rapid drying. it seems to have made a difference as an offcut from the bearer went unsealed & very quickly developed cracks between the grains from tangential shrinkage. the 300 long piece had cracking from the cut back into the timber about 30mm. timber which was end-grain sealed had little-no cracking depending on what type of sun it received

timber & decking was also treated with organoil's woodguard which has worked the treat. against the manufacturer's instructions we also put some on the green timber but the higher moisture content resulted in the timber refusing to soak the oil - the kiln-dried decking had no problems. there is to this day a light oily coating on the joists as i suspect they were cut in the second week, whereas the bearers & rail soaked more of the oil up as they had been cut the week earlier. in any case it has slowed the drying process & kept warping to a minimum. when i drilled the timber i noticed often a buildup of gases inside the drill-hole which 'fired a shot' of the small drilled bits of char back into my face as i withdrew from drilling the pilot - something i'd not experienced before & which continued to give me quite a surprise each time it happened! we think the gasses come from the moisture being heated by the cutting head; the timber being so dense it offers no escape - certainly this occurred more when drilling into the heartwood

sub-structure...
the posts were made up from two sticks of 100x50, bolted in 4 places along the length & sat firmly on a minimum 200 deep concrete pad footing (or adjacent to pipes, 300 to the underside of the pipe) in the bottom of a minimum 600 deep hole. coated all surfaces of the post timber with grated candle wax then ironed the wax to protect against wet-rot. ironbark is not susceptible to termite attack but it is to fungal - hopefully the sealing of all surfaces will prevent fungal attack from happening.

once the posts were made up & placed, clayey soil was backfilled around & tamped with the gal pipe every 150 or so. this is the first time i have used this method & i am happy with how it went, getting the best results from backfilling a bit to get the post squared up & held in place. final fine adjustment of the posts after the holes were backfilled proved easy by placing a rubber mallet against the post & striking it with a gympie hammer while the post was pulled in the direction you need it to go. the vibrations disrupt the soil slightly & allow the post to square up nicely, bit by bit. my brother & i got the four posts made, placed & the bearers mounted in a cruisy day.

[brynk]

the blood-gods will have their toll...
that evening over a beer, we started bringing joists out for the next day's festivities. the fine coating of oil had left my feet nice & slippery after walking around the oiling bay & also across lengths of timber as we carried them out from the pile in the shed - i decided to see if i could fly off the top concrete step - the bearer that was waiting there when i landed kindly broke my fall. the only downside being my hundred odd kilo's of bulk used my left rib-cage to soften the blow. though this was not the first, nor was it the last injury, it certainly slowed me down enough to consider my actions a little more carefully for the remainder of the construction!

with the joists mounted 'the hard way' along the front to the bearer, i decided that i couldn't make brackets from angle for the tie-back to the whaling plate that supports the joists along the house, and wound up cutting gal angle & fixing one side to the pine & the other side to the joists. this is certainly the method i should have used along the bearer also, and proved a mistake for the time taken to manufacture the brackets & also the installation involved a lot of bending, sitting, standing, lifting, repeat 19 times...

this pine ledge that the backs of the joists sat on also turned out to be a sting in the tail when i was doing some reading on durability & construction methods. the plate itself being unpainted, with no flashing installed, will fail long before the service life of the other timbers is reached. when it rains here this rain will sheet down the bricks & get trapped between the bricks & the pine, where it will hasten the demise of the untreated, uncoated pine rapidly. hindsight being 2020, i should have had a second bearer in conjunction with the front one & kept the entire deck separate from the house; and incidentally if the pine lasts until 2020 when i will have to crawl under there & instal said bearer then i'll be pleasantly surprised

xanthorroea johnsonii...
we couldn't bring ourselves to destroy a creature that we figured to be as old as both of us put together, nor attempt to move it when she is a convicted plant-murderer & i am a self-confessed brownthumb. so we decided to make a feature of it & box it in. heated debate was solved by a friend of ours suggesting we give it enough room to grow into, and enough of a 'stomp-zone' when someone slips of the edge & into the hole - it has worked out well but made for an interesting bit of construction when i remembered that the joists can't canti more than a percentage of the overall backspan (the reminder ofcourse being delivered physically, when i was testing the bending strength of the canti at the ends of the joists along the front of the deck!)

[brynk]

with the structure (almost) complete & noggings cut & placed between the joists which had shrunk unevenly on the y-axis, it was time to start mounting the decking. we opted to do a dry run to make sure it all worked out well. this proved to be a worthwhile pursuit, and made life much easier the following day when nailing commened.

prior to doing the dry run i strung out the square again using multiple methods to see how it all came together;
1) from the black-boy end where i stuffed up my right-triangle because i measured the hypotenuse off a joist under the sill of the window - because the sill is slightly recessed from the brickwork my right-triangle was slightly rotated, causing a bit of panic when i saw that 'square' didn't line up with 'grass'!
2) a repeat of the process from the other side of the house (the eastern end), which was one of my original datum, left me wondering until i figured the sill thing out; then finally, 3) measured out along each end joist 3000 to see how it lined up with the string already in place - phew, pretty good but that brickwork must be out - wavy stringlines they use to make back in the seventies!

after a bit of research on here as well as a csiro study we settled on 65mm x 2.8mm gal bullet-head nails, hand driven. i came back off the end of the deck at each end equal distances to the 3rd run out from the house & pulled another string, which i fixed a row of boards to. this would be my initial cramping run. i don't know how i did so well on the cramping run with the 65's because the next phase when i did my first real test of cramping with 3 runs i had a world of grief. i was pilot drilling then bending more nails than i was fixing successfully, and in between all this i decided 'my ribs weren't gettin any better, and well i just should go to the doctor' - an x-ray revealed i had 'no detectable fractures' so i'd hate to have a broken rib in the future cause this one hurt just enough, thanks you very much.

a trip back to puntings & we changed the second box of 65's for 50's & everything went smoothly after that. well, almost...

[brynk]

i love that 2m long irwin clamp i paid about 35 bucks for. i must say this clamp proved a versatile little addition to the tool chest. not only did it serve wonderfully in its role as a steadfast extra mate, but turn the head around & it becomes a toe, and all of a sudden you've got a light tall jack that is rated to 250 kg's

now well & truly away with the three runs taking me about 2 hours to fix in one pass, my spirits were quite high. the old man rang that night and after a brief discussion it was decided that he would come over to help the next day.

just des(s)erts...
we'd decided back in the design phase that 2mm either side of a decking board would make an acceptable gap, so i picked up some 4mm thick tassie oak stripping & made a bunch of packers. you can figure my method from the photos - and after a while the old man & i settled in on a good run. from the day before i knew it was warming up. something we hadn't figured was the reflective capacity of the decking - with the drill over-heating & the pilot template too hot to touch if it was left out in the sun between joists, pretty soon my head & concept of time started to wander, but by sheer benevolence from the toll paid, the line of the decking didn't!

we started at the eastern end and came out to the 2nd run that passed by the blackboy. the night before when i was thinking straight, i decided to leave the boards on the western side of blackie until after i had transferred my line across the 'gangway' as we have taken to calling it, that way if there was an error in square then i would have ten or so boards to fiddle the spacing on to bring it back to the house. when the old man set them after lunch they came in just right & i was happy as a pig-in.

though as the sun moved over the yard arm & the shade line started creeping across the deck, i was reminded once again to slow down a bit. we had already discovered in our haste filling in the western end that we (i, being the chief piloter & dad fixing where i had drilled) didn't leave that 2nd to last board unfixed so we could pull it out & have another cramping board to fix to the next day - the biggest stoopid was that it was only on those last 4 odd joists; the old man conviced me not to pull it up as i would stuff it & only create more work, and that i should use the extra cramping space i had to do another 2 along just that stretch past the gangway (made for some interesting thinking that night & the next day!). travelling along the deck up near the black boy after we had picked 2 likely candidates & got into it, i pushed the decking off the joist and put foot straight down past a stack of pavers. just as i was thinking '&^%$ that one hurt' my old mate archimedes reminded me of how stupid i was when the decking board that i had just stepped on pivotted on its joist-fulcrum and came up to drill me on the top of the head. through the peals of laughter the old man commented that he hadn't seen a cartoon that good since my brother and i used to wake him up on saturday mornings for the fest, you know, back when the cartoons were worth getting up for...

we decided at that point to call it a day, and over a beer proceeded to set out the next day's decking to be fixed. this certainly saved time in the morning & neighbourly relations by turning the hammer off at sundown each day; i had got to thinking that it was looking like a bloody long day tomorrow, and that there must be something i could do to speed things up a little. we decided on a nailing pattern that saw double nails at each join, one joist in from the join, then staggered singles in between. this would tide us over until i got keen & finished it up once i was over the shock of the initial construction.

i don't know if it did save time, but i took to placing the bright yellow lid (of the jar that contained the woodguard, which i was dipping my nails in by this stage before i hammered them) over the decking that i was not to drill. this certainly kept things in order & left me with one full loose run to cramp the next rows off. i think that day (friday) i managed about 17 sq.m's - near double the day before, double the day before that. by that evening i had managed to get through 1/2 way along the last 3, which can be seen sitting loosely on the end of the joists in the last shot. that left me with trimming the dags off each end & around the blackboy & fixing off the 2 runs closest the house - suffice-it to say that it was still a construction site at 5pm on the saturday with the first guests arriving at 6.30! ahh, pressure!

[Dirty Doogie]

Hi there Brynk! Looks like a job well done and should last a few decades I think. And I'm glad you decided to leave the Blackboy oops grasstree in place - judging by the size of it I would guess that it is about 30 - 40 years old.

I'm not sure that the weed mat should go right up to the trunk though. I know weedmat lets water through but i cant help but think that a lot of water is going to run away from the plant before it gets through.

good work - and good writing too!

Doog

[brynk]

thanks Doog, also for the tip on the water runoff - we are now considering a couple of options. as there is a hole in the gutter just near the tree itself which i am inclined to leave because it delivers a good bit of rain directly to the base of the tree, once in a blue moon that is. we are thinking about doing a bit of a channel back & across, with a slope to the base of the tree itself, maybe removing the weed mat to the drip-line if it is not ponding & staying. it was always gonna be a bit of error & trial anyways!

here are some photos i took this arvo of the end of phase 1. the next step is to instal the beer rail, which was in one of the earlier shots. the rail will extend for 5m, slightly offset from the centre. at either end there will be a step which carries through & turns the corner, running back towards the house about 1/2 the length of the deck. ultimately, the window will go & a door will give access to the loungeroom directly.

[Dirty Doogie]

Gee that decking timber looks good with the grasstree

- About the pine ledger piece youre worried about - if you havent put the final decking board against the wall down yet - you could always get some bitumen based water cleanup waterproofing stuff ( BitKote #3 I think from bunnings) and some waterproofing bandage and bandage across the the top of the ledger and onto the painted wall - ledger will last for - 50 years?? - a long time anyway.

[Loki429]

Great stuff Brynk! Looking really good.
I love the grasstree feature, plus the way you have slightly cantilevered the deck makes it look like its floating above the ground.

One suggestion for around the grasstree cutout would be to fit a "border" around the three edges, being a decking plank on its side and sitting about 25mm above deck level. This would provide a bit of a barrier to prevent shoes and things from falling over the edge (and copping a grass spike in the eye as you lean in there to retrieve it won't be fun...), and perhaps a stray foot from yourself or a guest falling in.

Keep up the photos and commentary, it is enjoyable and inspirational reading.

[pawnhead]

Wow, how did I miss this one. I usually check out all the decks going up around here.

Good job brynk. A great looking deck and a top yarn to boot.

the only downside being my hundred odd kilo's of bulk used my left rib-cage to soften the blow.

,,,wavy stringlines they use to make back in the seventies!

,,,i pushed the decking off the joist and put foot straight down past a stack of pavers. just as i was thinking '&^%$ that one hurt' my old mate archimedes reminded me of how stupid i was when the decking board that i had just stepped on pivotted on its joist-fulcrum and came up to drill me on the top of the head. through the peals of laughter the old man commented that he hadn't seen a cartoon that good since my brother and i used to wake him up on saturday mornings for the fest, you know, back when the cartoons were worth getting up for...

Happens to the best of us. Newton taught me how to get down three storeys in three seconds flat once.

[brynk]

gday again - apologies for neglecting my own post

dirty doog's; thanks for the suggestion regarding the water-proofing with bituminous compound. i purchased the netting but baulked at the price of this compound from hardware supply stores - i've encountered a very similar product in the automotive industry - underbody sound deadener ~ $12 / 4 litres & this is what i intend using.

loki; thanks for the suggestion regarding the border. our thinking at the moment is a mitred border made of the same decking material and mounted directly onto the decking at a 45-degree angle

pawnhead; glad you enjoyed the read newton has not seen fit (yet) to instruct me on the gravitational attraction a small mass feels to a much larger one... yet (looks for the 'touch wood' smiley)

>>>

progress since my last post; eer, i restacked the remaining ironbark in the garage to keep it out of direct sunlight and provide better airflow - it is seasoning nicely with minimal warping

am now looking at a new product for the deck coating done by a mob called lanotec - http://www.lanotec.com.au/?link=3 - i use their heavy-duty lanolin product on just about everything that needs lubing (hey i said 'just about everything'!) and i love it. the only thing it can't handle is direct rain, even though when heavily applied it creates a waxy, sticky film which water beads off nicely - this can attract dust & dirt also.

the organoil woodguard has been doing its job protecting the new decking while it settles into its role. i've had one short board twist slightly and lift the nails on an end joist; otherwise ive noticed a slight trend to cupping. the boards have definately moved a little as the joists have shrunk. every joist has a split along the top edge that was propogated by nailing & shrinkage - some of these are a couple of mm's or more.

we got some good rain here at the start of the month and it has given me a chance to observe the level deck's drainage capacity - virtually non-existant! this is definately a design flaw & i will probably go along the bearer and drop out a few of the packers and lower the joists a little to give the whole thing a fall; maybe all that rooting around with steel brackets along the face of the bearer has saved me a little drama after all... by the way, the water-delivery system (the hole in the gutter) keeps the native nice and moist when it rains - a rock placed judiciously under the drip and a bit of creative dirt-moulding has kept the water at the base of the tree nicely - the two shoots seen in photos have outgrown their predecessor and are now reaching for the guttering!

i've decided that the steps & beer rail need to be in for chrissy; well, new years is my target but i'll get nuthin done later in december so it's gonna be at the end of this month - i think the hardwood will have had enough time to stabilise in the garage and though it has still got a lot of drying to do, the moisture content will have dropped considerably from the time it was milled. onward & upward!

[brynk]

had a bit of a 'troop surge' on the deck with the warmer weather, to see if i can tie it all up before chrissy! anyway...

there are a first couple of shots showing the floating stair & seat feature. the apprentice's brother's wife suggested that a full-width beer rail, while much more accomodating to beer drinkers, would close off the back yard. i must have been a bit pissy & suggestible when the design was modified slightly, because it turned out to be a real pain in the arsky. hehehe. anyway, the stairs weren't quite as rigid as i'd hoped and i wound up have to chock with offcuts between the bottom arms of the brackets & pathways, until i can weld some adjustable feet on which will be more discreet, and permanent. the shot showing the stair at the darky's end - i swear that is a trick of the fisheye lens and not a 'height of embarrassment' .

there are also the three posts which support the chair/stair and to which the beer rail rests upon. the method i used to do this -

first of all clamp (who has since affectionately been dubbed 'steve') the rail at the base of the posts where it will sit at the top. (glad i had the forsight not to cut the dags off the end of the joists eh? )

next, get some cardboard and take an imprint of the top of the post. cut it out with a knife and check it against the top of the post again. repeat until satisfied. be sure to mark the top & left side of the cardboard so i can flip the cardboard over to transpose the outline for routing (damn i forgot to mark it and shyte, i'm running out of cardboard). ok that is sorted. i have an idea! i can make the cardboard a little smaller so it is a tight fit - an interference fit they call it in the mechanical trades.

next, pull a stringline along the base of the posts to work out any centre-line error (yep, they're out by about 5 mm from the centre post) which will need to be allowed for in the placement of the holes in the underside of the rail. this will also show if the rail is truly straight (nuh, it isn't). so now the error and the bentness can be allowed when measuring for the centre of the underside of the rail and placing the hole square to the base of the post. i have no doubt that the rail itself has the strength to pull the posts out of square & plumb (or into as the case may be) if they are checked into the wrong spot, so careful placement of the holes will pay dividends when it comes time to do the eating.

when i mounted the posts i tried to make the outside ones both bow out and got the straightest one for the centre. these forces will hopefully balance each other out, the posts will be plumb once they are checked in and i wont need to use brackets... hahahahaa . you can also see the shot where there is a couple of offcuts clamped to each side of the post at the top - this is to support the router so post can be rebated properly, rather than cut with a handsaw and sanded as i tried originally

ok so i am happy with the placement of the holes - next it is time to rout each of them and check to make sure the cardboard is fitting good. yep beauty.

flip the rail over and lift it into posy. put steve to work holding one end while i slot the other end in. damn stupid mongrel interference fit. where's me mallet. *5 minutes of loud pounding transpires* ... beer... those interference fits sure work better when you intefere with the chisel!

you can see one post had a definite twist. no need to panic. i waited until i had an extra set of hands, then i mounted a sash-clamp to the top of the post so a rotational force could be applied by one of us, while the other flogged the crap out of it with the mallet. no wuckers...

now to be a total mongrel and not post a panoramic view just yet. finished fixing off all the decking boards which were left over that needed to be slotted in around damn water pipes and sewer vents and down pipes and crap. ofcourse, the boards that were stored in the garage all summer have gone down schmicko... which detracts from the other ones. so crap if i'm not gonna sand it and oil it again. i read one of the professional floor guys here considers a well-finished deck to have no roughness across the grain. well, that is the standard so i will have to sand it...