# Forum Home Renovation Pergolas, Gazebos, Strombellas & Rotundas  fascia fix - ?? rafter stiffening

## jul1313

hi 
Just had a pergola built 5m long by 4.8m wide pitched roof, covered in laserlight and fixed to the fascia (on the 5m length). I had it built by some old builders who have done a lot of work for me in the past and everything else they have done is perfect but some things look a bit odd about the pergola. 
firstly and my main concern is the fascia fix with lack of anything done to the house rafters. 
They have just put the 140x45 rafters (pergola) straight into the timber fascia with joist hangers, and then batten screwed the fascia onto the end of the house rafters. Is this the normal way of doing it or should something be done to the house rafters for added support ??  
I had a look at the house rafters and they are 120x50 hardwood (50+ year old house) with a 450mm overhang for the eaves and the majority of the pergola sits over the Lintel above the 4m bifold doors which would make it difficult to frame the rafters back to the wall frame anyway.  
This thread   http://www.renovateforum.com/f204/pe...-newbie-62319/       got me even more concerned about rafters failing etc.... (I know this refers to metal fascia but i assume same principals)  
The other concern I have is that the posts were not checked out for the beam instead the beam was just fixed on the outside of the posts with 2 x 100mm batten screws through the beam into each post..... once again don't know if this is normal or not.  
Thanks in advance for any advice

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## METRIX

Hi, If we are fixing to an existing fascia we will batten out the rafter ends and fix a new ledger all the way along the fascia with M10 or M12 bolts, then the pergola rafters are fixed into the new ledger, depending on the rafter situation the use of metal bracket tied back into the house structure may also be necessary. 
If they have just used hangers and a few batten screws to hold up such a large structure, even if it is only covered in laserlite, there is still a lot of weight up there, and I would not be going under it, without some acrow props to hold it up until it can be supported properly. 
Not checking out the post is NOT normal, the posts should be check out so the load is transferred onto the post, currently your load is being supported by the batten screws only ?  :Yikes2: , these are suitable for holding DOWN battens, or board-walks etc, NOT for holding UP a pergola. 
If the beam is 45mm thick then the post needs to be checked out 45mm, and at minimum of two M10 or M12 bolts should be used to secure each connection. 
With a notched post the bolts are not actually taking and of the downward load as the notch is transferring the load to the post, saying that it is possible to design a connection point to NOT use a notch in the post but you would need to use M12 bolts NOT batten screws.  
Honestly I would not be walking under such a huge structure that is only supported by two 100mm batten screws and no checked out posts, I would get the guys back to fix it properly ASAP, the first gust of wind could see your new pergola disappear into your neighbours.  
We have been to similar structures which were held up with similar [or worse] methods, our visit was not to paint the structure it was to pick up the pieces when it all came crashing down, luckily nobody has been hurt by the ones we have seen broken. 
i assume your "Builder" has some sort of license to say he is a builder, and was this "approved" by a certifier or council, as there is NO WAY either would approve such a structural disaster waiting to happen.

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## baileyboy

How much checking is required? I recently put some roof beams (on a 5 x 7 deck). Roof is cathedral type. Because my post ain't completely in line, I checked the corner posts 2.5cm, the middle posts 1.5cm. Is this sufficient? Now that you got me worried... 
My beams are 200 x 50 LVLs.

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## METRIX

> How much checking is required? I recently put some roof beams (on a 5 x 7 deck). Roof is cathedral type. Because my post ain't completely in line, I checked the corner posts 2.5cm, the middle posts 1.5cm. Is this sufficient? Now that you got me worried... 
> My beams are 200 x 50 LVLs.

  
Our normal practice is to notch out the full depth of the supporting beam, so for your 200x50 LVL we would notch out 50mm from the post. 
The rule we follow is to NOT notch out any more than 2/3 of the post, so for a 90mm post you should be leaving at least 30mm un notched, so a 50mm beam can be notched for full depth in a 90mm post, but if it was a thicker beam we always move up to a larger post. 
For your situation it is ok what you have done, as long as you have attached these with M12 bolts, as your bolts are taking a greater proportion of the load which would normally be transferred to the post with a full notch. 
If situation calls for not fully notching we would do 25mm notch on all posts but yours with 15mm is still ok, as there is enough shoulder to support the beam, but any smaller than 15mm I would not recommend. 
My above concerns were with the OP which the posts were held up with batten screws and no notching, a big NO NO.

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## baileyboy

Thanks. I have attached some photos as well. I'm a bit concerned now. I'll probably will remove them and then re-notch...  
The corner posts are 135mm so I guess I can notch them a bit further. My only problem is that they are up in the air and getting them up there had been a mission.

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## METRIX

Hi Bailey,  
I would not be concerned, your mounting looks good, I would be a more concerned that you have used a LVL in an open unprotected situation. 
LVL should not be used in an un protected situation such as a Pergola without a roof on it, as water can affect the lamination's of the LVL and cause them to break down. 
See attached LVL Design Guide, you should give this some consideration for long term stability of the timber beams.

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## baileyboy

Thanks Metrix, 
I think I'll redo the beams. I don't want to lose sleep over it in future.  
There were H3 LVLs which I was told can be used outdoors. I'll eventually put a roof over it so at the moment (thinking at my current rate, it will be a good 6 weeks). I've put 3 coats of solarguard on it just to protect it for the time being. Do you think that's ok? I can get some gladwrap and wrap it up...

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## METRIX

If it makes you feel better to notch them in further then by all means, bear in mind it will change the position of where you have mounted the posts to the ground as the post will move the extra amount notched, it really is not necessary for you to notch them more as what you have done is ok, I assume you are putting colorbond or laserlite etc on the pergola ? 
I wouldn't worry about wrapping the LVL it is not necessary you are to put a roof on it in 6 weeks this is fine, When we do an extension, we may leave UNPROTECTED LVL for about 5-6 weeks and these have no side effect, they have a wax H2o coating on them to protect them short term from the weather, it is only if you were leaving them unprotected permanently that I would be concerned. 
You you have 3 coats of solagard this will protect them until you can cover them with a roof, no point loosing sleep over something like this and no need to undo your good work.. 
As you see below from the design guide H3 LVL is NOT recommended for Pergola which is exposed, but put a roof on it and it's ok as long as the LVL is protected from the weather
The H3 treatment is mainly for Termites and not for water damage causing Rot due to the possibility of it getting into the laminations of the LVL.   (iii) Construction detailing to prevent water entrapment. 
H3 treated SmartLVL is NOT recommended for fascia's, pergolas or other similar external above ground, exposed applications due to mechanical degradation of the wood fibre causing checking and cracking which is both aesthetically unacceptable and allows ingress of water to inner

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## baileyboy

Thanks Metrix. I've notched them all out so sits flash with the posts. All the cut timber were either oiled/painted so I think it should protect it while I finish the rest. However, I noticed that there are some cracks. I asked the supplier and he said its just the first layer of the laminate, just wondering if you experienced this. 
Also, do you know if it is ok to nail LVL in the direction of the laminate. Doesn't seem right...

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## Pulse

14G batten screws have a shear strength of about 10kN  or about 1000kg each (source - Buildex website) 
M10 bolts are about 20-30kN in shear. 
The uplift forces are larger on a laser light pergola than the dead and live load. The following table from AS1684.2 shows 3 batten screws is stronger than 2 M10 coach screws when screwing into end-grain rafters.   
Assuming N1, the uplift is 1.31kPa within 1.2m of edges and 0.68kPa remainder of roof. If there are two posts on the 5m edge then you need about 9kN for uplift so the batten screws may not be enough, depending on timber type.  
This table shows that 2 batten screws actually exceed the uplift capacity of 2/M10 bolts in a few situations (don't ask me why?) 
Cheers
Pulse

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## METRIX

> Thanks Metrix. I've notched them all out so sits flash with the posts. All the cut timber were either oiled/painted so I think it should protect it while I finish the rest. However, I noticed that there are some cracks. I asked the supplier and he said its just the first layer of the laminate, just wondering if you experienced this. 
> Also, do you know if it is ok to nail LVL in the direction of the laminate. Doesn't seem right...

  Do you have a pic of the cracks ? 
Nailing in the direction of the laminates, sometimes this can't be helped, such as when fixing rafters to a ridge and nailing from the back of the ridge into the end of the LVL, we only use this as a temporary hold then skew back through the LVL into the ridge. 
LVL being a laminated timber, I would preference to nail through the laminates rather than with them, what is the situation which calls for nailing into the laminates you have ?

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## baileyboy

I'm using the Pryda pagoda brackets to connect the truss onto the beams. 
I'll take photos tonight. Cheers.

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## METRIX

I see, fixing the pergola brackets along the LVL grain, you shouldn't have a problem, if you are a bit concerned, put some roofing screws into the LVL Laminates, you wont see the heads as they are up hign and hidden on top of the LVL. 
Use Pyda connector nails into the face of the Rafters, don't use ordinary clouts as these are weak and the heads will collapse if there is excessive force put on them, the pryda nails are designed for structural purposes to not fail when needed.

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