Pergola construction help!!

[Andrew Osborne]

I'm planning on building a pergola on our new house - just open no roofing.
I have two problems - firstly how to attach it to the house.
It is a new house and has a colorbond fascia around the eve and roof beam ends behind that (i think).
For the support I want to fix a beam - probably 140 x 45 to the fascia.
How do I do this... with batten screws or rafter bolts or some sort of angle steel?

From this I want to fix the rafters out to poles and beams about 5.5m away.
Will 190x45 F7 treated pine do the job if I put a cross beam down the centre or will it be better to go for 240x45?

The total length will be 12m along the house and 5.5 - 6m out to the support poles.
Looking forward to reading your comments,
Andrew

[GCP310]

get yourself some of the Allen Stains series of construction books. They are excellent and really well priced. Bunnings stock them. i have the House Building and Decks & Pagolas books.

Failing that,Seek professional advice :D

G

[wombat47]

http://www.bowens.com.au/images/howto/Bowens_Pergola.pdf

has detailed instructions, including timber dimensions, for building a pergola.

[Andrew Osborne]

Thanks guys, I did get pro. help and that's why I'm confused.
I'm ok with all the building - but how do I attach my wood to the fascia?
Has anyone heard of these "rafter bolts"?
Looking forward to your thoughts...

[adrian]

The people who previously owned my house bolted the header (I think that's what it's called) directly to the outside wall of the house under the eave. The problem is that the windows go right up to the eave so you can see about 70mm of the beam across the top of the kitchen window. It's poor work but it's only really noticable since I took the pelmet off the window.

I'm not a builder so I can't offer any worthwhile advice about construction methods but I can offer some practical advice about future use. I was thinking about all the people I know who have done something similar and I can't think of anyone who didn't end up completely enclosing the area or at least putting a roof on. So I would build it as if I was going to put a roof on and enclose it in the future. This means that you have to take into account the distance between any future roof and the existing roof.

[DaveInOz]

What I have been advised ...... but not got round to doing yet ....

Where the fascia will not support the 'header' beam lift the tiles and fix reinforcing blocks between the rafters against the fascia (secured to the rafters), then attach the beam through the facia into the reinforcing blocks.

[wombat47]

On the top of Page 3 of that Bowens Instruction sheet, it says to fix a 150mm x 38mm fascia cleat across the fascia using 150mm coach bolts into every other rafter. Then attach hangers to cleat using coach bolts.

Personally, I think I'd fix it to the wall just under the eaves.

[jackiew]

Personally, I think I'd fix it to the wall just under the eaves.

do you mean the wall or the house frame through the wall?

[Jacksin]

I dont know if you have them where you are but I have seen long galvanised steel right angled brackets to suit the roof pitch, that fix to the side of the rafters, and sit inside the steel fascia for you to attach the beam to.

Sorry I dont know their technical name but they are sold here in any decent timber yard as part of pergola fittings.
Good Luck
Jack ;)

[wombat47]

My apologies ... I've always lived in old brick houses and it's affected the thinking processes. I forget there are different kinds of buildings.

So, Andrew, if it's not double brick, ignore my suggestion of fixing to the wall.

[Andrew Osborne]

I dont know if you have them where you are but I have seen long galvanised steel right angled brackets to suit the roof pitch, that fix to the side of the rafters, and sit inside the steel fascia for you to attach the beam to.

Sorry I dont know their technical name but they are sold here in any decent timber yard as part of pergola fittings.
Good Luck
Jack ;)
Hi Jack and others,
thankyou for your help, I've just gotten some of these brackets from Bunning's.
They're called fascia support brackets and they bolt onto rafters with three bolts and rest behind the metal (tin) fascia. I'll then drill through the tin and bolt my new treated pine fascia to this bracket. I'll also alternate with a batten screw for a bit of extra support. The guy at the shop said it would never fall off... what are your thoughts?
looking forward to your reply...

[Jacksin]

Andrew I have been thinking about these fascia support brackets etc and what concerns me, and Mick will probably help you here, is that you are hanging a lot more weight on the overhanging section of the rafter. I wonder if you should beef up or brace the rafter before fixing the fascia brackets.

Some of these pergolas are over timbered to look nice and 'chunky' without bothering about the weight factor.

Its just a thought.
Jack ;)

[Andrew Osborne]

Hi Jack,
By Beefing up do you mean steel on the otherside as well or just more wood?
Will a Bracket then a long batten screw on every other rafter do?
Looking forward to your reply...

[Jacksin]

Yeh either way Andrew. I was actually hoping Mick would come to your rescue with the best option. Perhaps you could PM him
Jack ;)

[journeyman Mick]

Andrew,
I wouldn't batten screw into the ends of your trusses, end grain doesn't hold screws very well and as most trusses are either 32 - 38mm hardwood or 45mm pine there's a good chance you'll just blow out the end of the timber. Otherwise the brackets should work fine.
Jack's raised a good point, the extra loading that the trusses weren't designed for. If the brackets go back or fairly close to over the wall or beam then it shouldn't be a problem. If they don't perhaps reinforcing the bottom chord of the truss with some timber framing that extends back over the wall and maybe a metre further will help spread the load. On the other hand trusses are designed to flex in order to accomodate changing loads (wind, rain, expansion/contraction of roofing iron) and extra framing or your brackets may inhibit this. I hadn't commented before as I was thinking about all these things - really an engineer's field. As I live in a cyclonic area I don't generally touch anything like this without an engineer's drawing. Sorry, I can't give any real answers. :(

Mick

[IanA]

Both Mick and Jack have commented on the added loading on the cantilevered rafters or truss top chord. I think this needs needs a closer look before you get started.

If you think there is ever a possibility of roofing all or part of the pergola at some later date (Many people decide to add laser lite or something similar) you could be adding large wind loading into the equation. Best to plan for this possibility from the outset.

You don't mention how wide your eaves are. There is a big difference in how much load can be added if the eaves are 450mm compared to 900mm. Truss spacing will similarly have a large influence.

My suggestion is to have a talk to one of the truss manufacturers about what they recommend to support the additional loading. My guess is that they may have been called in from time to time to rectify the results of over loading.

Probably worth having a close look at the trusses and having some specific measurements and details to hand when you speak to the truss people.