Roof Plans 2

Bob Hart · Post by **Bob Hart** » Tue Oct 23, 2007 9:05 pm

OK so I decided to go wth the majority and have a pitched roof, but how to construct it?

I take it I dont need a 12-metre length supporting beam and I can just fit the main upstanding posts on the front and back walls of the pond and timbers connecting between them as previously.

So if the pitched timbers are then fitted to the connecting timbers and pointing on the angle upwards to meet each other, and these be fixed to a centre beam which runs the length of the pond?
[img]http://www.koipix.com/gallery/albums/userpi ... ng%203.JPG[/img]

Or would I need cross beams as well? Hopefully not!!!!!
[img]http://www.koipix.com/gallery/albums/userpi ... %202.1.JPG[/img]

dave a · Post by **dave a** » Tue Oct 23, 2007 10:17 pm

yes you need a cross beam to complete the triangle otherwise it will flex in any direction it likes and the structure will be unstable the cross beam can be at a higher level though but you must complete triangalation of the truss

Telthepondman · Post by **Telthepondman** » Tue Oct 23, 2007 10:51 pm

Hi Bob, Dave is correct you do need some type of triangulation, you could try a triangular ply plate screwed and glued to both rafters at high level with the bottom of it level with the bottom of the white panel of your neighbours over the back of you, as in your photo. The ply would need to be 3/4" thick external grade and treated and screwed and waterproof glued with 2" no 10 screws at about 6" centres in pairs.I have used this a lot and it works very well. The ply plate can be shaped, say with a curved bottom or even decorative holes in it for a pleasing look.maybe even a Japanese type pattern easily performed with a jigsaw, just use your imagination but don't take to much out of the centre or you will start to lose the strength.You will need a plate on each pair of rafters the complete length of the roof. By the looks of your photo the rafters look about 10 feet long so your rafters need to be a minimum of 6" x 2" timber. For added strength you could add a decorative plate as before to the bottom of the rafter on the joint where it meets the upright post. I hope this has been of some help. Tel.

dave a · Post by **dave a** » Wed Oct 24, 2007 4:18 pm

the other alternative is to run a purlin each side supported from main trusses the main trusses need to be 6x2 rafters with trianglation and would need to be at 6-0 centres the intermediate rafters then could be 4x2 as the span will be split by the purlin either side.

I would be carefull with a ply plate at high level as the force down the rafter legs will still tend to spread at low level in an ideal world the triangluation needs to be in the centre.

vippymini · Post by **vippymini** » Wed Oct 24, 2007 4:46 pm

do you mean pieces of plywood like this.
i think it would look better than the cross brace

dave a · Post by **dave a** » Wed Oct 24, 2007 6:21 pm

no not correct read the post as outlined below it needs to be at the top at the junction of both rafters

Quote "a triangular ply plate screwed and glued to both rafters at high level with the bottom of it level with the bottom of the white panel of your neighbours fence" unquote

StuW · Post by **StuW** » Wed Oct 24, 2007 6:28 pm

Cross beam would be structurally stronger than Triangulated plates at the top but if you dont like the aesthetics you could always use a tensioned wire holding the base together while tying the foot of the trusses to the base structure on a bearing plate running between each truss.

Telthepondman · Post by **Telthepondman** » Wed Oct 24, 2007 6:57 pm

Hi again, lots of interesting comments, all constructive. If you read my ply plate suggestion the bottom would end up at about half way down the rafter leg as has been commented on. I like the tensioned wire idea, preferably stainless steel available from most boat chandlers but not cheap.You are on the right lines with your bottom plate sketch, but they would have more effect if face fixed as before described and then shaped, curved for instance. Tel.

tomy2ponds · Post by **tomy2ponds** » Wed Oct 24, 2007 7:08 pm

Bob if you went for the ply idea you could cut Koi shapes in them then they would look better

LEE

vippymini · Post by **vippymini** » Wed Oct 24, 2007 7:12 pm

ok like this at the apex then.
p.s. like the steel wire idea

Telthepondman · Post by **Telthepondman** » Wed Oct 24, 2007 7:17 pm

Now we are cooking.Tel

Bob Hart · Post by **Bob Hart** » Wed Oct 24, 2007 7:43 pm

Dave/Tel/Jane/Lee/Stuart,

Really appreciate the posts you have all made, certainly given me something to really think abaout.

I'll do some more drawings soon for further comment, based on what you've all said - thanks again

Gazza · Post by **Gazza** » Wed Oct 24, 2007 7:52 pm

What about a conservatory over it Bob

Some good stuff guys and this will be some pergola when finished and i love the pitched roof idea

dave a · Post by **dave a** » Thu Oct 25, 2007 5:55 am

ply plates either sides of the rafters face fixed would be better no strength in screwing through 2" timbers into 3/4" ply

PGREEN1011 · Post by **PGREEN1011** » Fri Oct 26, 2007 7:45 am

Hi Bob,
Have you seen this?
[url]http://www.woodsshop.com/JapaneseAzumaya.htm[/url]

Paul