Needs Pictures: 0
Picture(s) thanks: 0
Results 1 to 15 of 35
-
14th December 2014, 08:46 PM #1
Cladding the outside of a shed with Cypress pine (T&G floor) - questions please....
I have 68 m² of Cypress Pine flooring, which is currently Tongue and Groove:
https://www.woodworkforums.com/showth...97#post1811397
I have now taken all the pallets apart, stacked and sorted the palings. Next year I will be embarking upon a shed extension, and my intention is to use the Cypress paling for cladding the outside.
I'm not sure yet if I will paint (probably cream Solaguard if I do), or use a clear Solaguard or similar. The latter is my preference as the timber has some very nice colour and figure, but I'm not sure how long that would last in the sun (not that we've had much in the last fortnight ).
So, first request is what clear product would you think is the best for longevity please?
The next conundrum is how to machine the boards, and whether to run them horizontal or vertical. But first a little background.
There will be two faces of the shed that are "on display" as it were and score heaps of direct sunlight (north and west with nil shade), and two faces where the appearance doesn't matter too much (and these two don't get much sun - east is shaded by trees, and south just doesn't get any).
In another thread, someone suggested a Shiplap joint. Well a T&G is more or less a double Shiplap so I could either leave the T&G as it is or machine off the bottom edge of the Groove side which would pretty much make it a Shiplap with variation. I think leaving it as full T&G would be fraught with swelling difficulties, even though the timber would be sealed with Solaguard of some type. What say you?
Let's assume for the moment that the consensus is to make a variation of the T&G. Normally the boards are cramped up tight but this again would be a bad idea. How much gap between the top of the boards should I leave (again remembering that they will be sealed). Would 2mm be enough for expansion? If they were unsealed I'd probably leave 5-6mm, so I assume that I could get away with less.
On the same assumption (Shiplap variation), would there be any difference in running them vertically or horizontally? Vertical would mean that there is no little shelf for water to accumulate on each board, but also means that the most susceptible end grain where the boards meet end to end would be horizontal. The end grain will be well sealed with whatever finish I end up choosing and if I cut the boards nice and square then there shouldn't be too much room for moisture to get in (but that wouldn't allow for any length expansion due to moisture - should be ok?).
Probably important to note that the boards are maximum 1800 mm long, most common length is around 900-1200 mm. They will be screwed to the frame with gal plated screws.
-
14th December 2014 08:46 PM # ADSGoogle Adsense Advertisement
- Join Date
- Always
- Location
- Advertising world
- Posts
- Many
-
14th December 2014, 09:39 PM #2
Hi Brett
run the boards vertically, they are too narrow to lay them overlapping like weather boards.
lap the boards as for a fence -- this will overcome swelling / shrinkage problems
If boards are too short for a single run, use a 30° scarf joint with a bit of overlap to protect the end grain
I suggest copper nails -- you used to be able to buy them in 5kg boxes -- rather than gal screwsregards from Alberta, Canada
ian
-
14th December 2014, 10:21 PM #3
Vertical is the way to go
Sikens or Feast Watson for a natural look, Solargard for painted (DON'T use Weathershield, its crap) but if natural, remove any old sealers or coatings first
DO MAKE SURE that you give the back of the boards and tongues/grooves a good coat as well, minimizes the movement of the boards ie weather changes, cupping, splitting
Use stainless steal decking nails (they come in a plastic coil, just peal out) or SS square drive (Robson) decking screws BUT pre drill over size to shank of nail or screw, cypress especially old, moves with climatic changes and splits very easily if not pre drilled
Leave 1mm gape in joints, 2 layers cheap sarking or 1 layer heavy duty roof sarking on frame first
45deg end joints sealed with Sika flex in appropriate color
15 deg cut to bottom of boards at bearer level and seal with SikaflexThe person who never made a mistake never made anything
Cheers
Ray
-
15th December 2014, 09:19 AM #4
Brett
Timber only expands and contracts through it's width and not the length. Any gap top to bottom should only be for movement in the building itself and not the boards. If you follow the scarf joint recommendation that problem should be eliminated.
I would never again use a clear finish anywhere that was exposed to direct sun. It would be a constant (probably yearly) task to keep up the maintenance. Ask the boat people. Left untreated it will last very little time at all. The house I built thirty years ago had ironbark framed, ledged and braced external doors. They looked magnificent for one year, but it took only four years for the varnish to completely peel off. Never again!
All screw holes will have to be pre-drilled in old cypress. Just par for the course.
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
-
15th December 2014, 09:11 PM #5
-
16th December 2014, 12:56 AM #6
Forget the Titebond, the differential movement between the 2 boards owing to such a wide range in timber density in cypress and the better than even chance one piece will have a knot near the end as opposed to the other not having a knot near the end will determine which one moves more than the mating piece, use Sikaflex of the appropriate color for the scarf joints and the 60 degree cut will split more readily than 45deg, go to 30deg and better still.
Your correct about the reason for the cut at the bottom of the board.
There used to be a product called Forestwood, it was an external based oil available in clear to a selection of tints and is good for external timbers. For recoating each year or 6 monthly, a rub down with a wire brush and good to recoat. Same applies for Sikens or Fest WatsonThe person who never made a mistake never made anything
Cheers
Ray
-
17th December 2014, 04:19 PM #7
Brett
A little bit of clarification needed I guess. Firstly, and this is also my disclaimer, tend to do what I say rather than do what I do . A lot of my advice is OK, but I don't always follow it myself .
The Ute box was a good example of both me not following my own advice and also of the breakdown of the finish. In that particular case the moisture got underneath the sealing coat and escalated the degrading while I watched. I spoke with the manufacturer in that instance and they concluded I had used the wrong glue. A point to mention here is that with your boards, which also are tongued and grooved like my ute box, there is no seal in the joints so moisture will have easy access causing premature breakdown.
The clarification of clear coats is to distinguish between sealing finishes and preservative finishes, which I suppose is how you would describe the oil finishes. It is the sealers (varnish etc) which I don't recommend for outdoor/exposed positions.
The oil finishes still need frequent applications, but it is a cinch to do. Also they tend to be used for smaller items such as BBQ furniture as opposed to buildings.
I was going to tentatively suggest you could finger joint the boards together to achieve full length boards, but Ray has raised an issue I hadn't considered. If you were prepared to "cut and shut" to ensure your joints were in good, solid timber it might work, but I have not done this. Modern fascia boards are often prepared in this way from much shorter lengths than yours.
The biggest catch there is they have a finger jointing machine set up, which cuts the joints, applies glue and press fits on a production line. You may have a couple of other things you would like to do.
I hope that helps.
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
-
22nd December 2014, 10:44 AM #8
Hi Ray
I have now milled all the boards 90x19mm, removing all the T&G (resulting in about 10 years with of kindling for the firebox ).
I want to cut the boards to certain lengths for ease of stacking and to cut off defects such as splits. I'll probably use lengths in 50mm increments as I think I'll only have *just enough* of these good boards for the walls that I will use a clear finish on. For using Ian's suggestion of lapping the boards (which I think is the way to go, and will look quite good) I would need three 90mm boards to cover a 220mm width because:
- I would leave a gap of 40mm between the two back boards
- which allows for a 25mm overlap on each front board (so that a screw will be 12½mm from each edge of a given back and front)
When cutting to length, I am considering cutting the mitres which will save on doing a second round of cuts later (doubling up the cutting). Each board would be a parallelogram where the bottom placed mitre slopes up from the front of the board to the back to avoid moisture retention in rain. The top placed mitre would be complementary to that of course.
So, the question is: given that I would like to put a couple of coats of clear on the boards before they go up, and I would like to do that asap to get the boards sealed (particularly the end grain). Will sealing the end grain with (say) Solaguard interfere with the Sikkaflex that goes into this mitred joint during erection? The way I see it the Sikkaflex is there to create a seal in the joint, and therefore not to actually glue the joint. Two screws either side of the joint will keep them well in place, along with one screw in the middle of each board at every nogging along the length.
I have stacks of noggings from the Club demolition, and sufficient other timber to cut more. My idea is to rotate the noggings 90° from the traditional placement so that a 100mm face is presented vertically for attaching the boards to. This is because I want to put the screws into the Cypress well back from the board end for obvious reasons (remembering that a countersink screw head will also split a board if driven too far home - as impact drivers are want to do). Using a 100mm nogging face will allow me to put the screws in about 35-40mm back from the middle of each mitred joint.
Of course that means that the noggings used for the outside boards won't be anywhere near flush with the inside of the frame, for fixing the interior cladding. That's no big deal for two reasons a) the cladding is likely to be MDF or plywood sheets (like Andy's) and can just be fixed to the studs, and b) if I need some noggings I can still add them to be flush with the inside face
I know that might be a bit complex to get into the mind's eye, so I can produce a diagram(s) if it will assist.
-
22nd December 2014, 02:55 PM #9
Noggins rotated 90deg YES
Solargaurd before Sikaflex NO, the Sikaflex takes about an hour before starting to skin up, just use a scraper to apply a smear to the mitre cut when you pre cut your boards and then a bead to the under cut as you fix the boards in place and yes the Sikaflex acts a glue as well the best part is it expands and contracts without breaking the bond and still maintains its adhesive properties and waterproofing.The person who never made a mistake never made anything
Cheers
Ray
-
22nd December 2014, 03:06 PM #10
Thanks Ray.
So to be clear:
- mitre cut the boards to length (which I am doing now)
- apply a smear of Sikkaflex to the mitres to seal, and let dry
- apply two coats of Solaguard to the rest of the board (and wipe off any from the mitre)
Then, when screwing the boards in place during construction:
- apply a bead of Sikkaflex to the undercut mitre and screw the board down (that is, Sikkaflex on top of the already dried smear of Sikkaflex)
- add the third coat of Solaguard to the construction.
-
22nd December 2014, 04:43 PM #11
Hmmm just had a thought......
Rather then overlapping the boards, how would it go if I just butted them up and put a thickish bead of Sikkaflex in between them (say it ended up as 1-2mm)? It would allow for some expansion of the sealed boards, but there would be two very important benefits:
- it would make the timber cover significantly more area (and I'm looking like a short supply for overlapping)
- it would mean that the walls could be lightly sanded down before recoating in the future - this wouldn't be possible to do with an ROS sander if they were overlapped as I would only be able to sand the top board - and bugger hand sanding the valleys and edges!
-
22nd December 2014, 10:06 PM #12GOLD MEMBER
- Join Date
- Jun 2005
- Location
- Helensburgh
- Posts
- 7,696
Why do you want to use Sikaflex when a good Silicone will do the job. If you put a waterproof membrane on the frame first leakage through the boards is a non issue. Splitting due to driving screws can be avoided by using a drill with a clutch after the screw hole is pre drilled and countersunk. I reckon I have done at least 5000 screws this way with no issues. Use a countersink that can be adjusted for depth as it makes the job a lot easier. An impact driver will make an easy job much harder and they are bloody noisy things for no gain on a job like this.
CHRIS
-
23rd December 2014, 02:04 AM #13
Yes to both your posts and NO to any silicon it will separate from the timber and moister will get in also to remove excess squeeze out will smear onto the adjacent faces or if you let cure it is a PITA to remove. Silicon does not have as much elasticity as Sikaflex in tension and any spots that do smear can be painted without any worries where as silicon does not take paint even the so called paintable silicons are a dismal failure. Stay away from the pre colored caulking compounds as well, if they are not exposed to weather they are so so but if exposed, fail very quickly.
Expect to pay 2 to 3 times the price for Sikaflex as opposed to siliconThe person who never made a mistake never made anything
Cheers
Ray
-
23rd December 2014, 10:26 AM #14GOLD MEMBER
- Join Date
- Jun 2005
- Location
- Helensburgh
- Posts
- 7,696
-
23rd December 2014, 01:00 PM #15GOLD MEMBER
- Join Date
- Aug 2011
- Location
- bilpin
- Posts
- 3,559
Brett,
Have you considered over moulding the vertical joints? This will allow you to sand up the outer face once boards are fixed, paint the face then screw a D batten over each joint. I say screw, as that allows the battens to be removed for sanding and easy repainting in the future. No real need to caulk the joints.
Similar Threads
-
western red cedar vs cypress pine cladding
By panos in forum TIMBERReplies: 10Last Post: 11th May 2009, 08:15 PM -
Cypress Pine floor -what stain & varnish to use?
By Samwise in forum FINISHINGReplies: 3Last Post: 9th March 2008, 03:36 PM -
Cypress Pine floor -what stain & varnish to use?
By Samwise in forum TIMBERReplies: 1Last Post: 9th March 2008, 11:59 AM