pergola fascia fixing - newbie

[ozizu]

Hi everyone, im just a newbie to all of this and would like some info on putting up a pergola. basically the pergola is going to be roughly 3m by 7-8 mrts in measurement with a pitch roof and is going to covered with some sort of laserlite. I have colourbond fascias currently and have noticed that when i lift the roof tiles, that there is a gap between the end of the roof rafter and the fascia. I have bought the pergola design book from bunnings which helps and have researched also. My questions are:

1. Fixing of the pitch roof to the fascia - someone has suggested simply popriveting the joist hangers into the fascia and that would be safe as houses. I am not sure about that!. Could i simply attach a piece of timber onto the end of the rafter in the roof to get it touching the fascia so then i could attach a ledger timber beam onto the fascia which then i could attach the pitched roof onto? Is that the best way to go for me?

2. Since i am putting the posts up against the existing colourbond posts of my fence so it looks neater i have had to dig up around the old post as far as i can go, but depth wise im only 250mm deep but 350mm in lenght and width. Been told to simply fill the hole with concrete and put a post bracket onto it, instead of using a post stirrup and stickm that into the wet concrete.

Any advise would be of great assistance. Sorry if i seem a little on the amateur side.

[artme]

Welcome to the madhouse. Ozizu.

[Tool-Horder]

2. Since i am putting the posts up against the existing colourbond posts of my fence so it looks neater i have had to dig up around the old post as far as i can go, but depth wise im only 250mm deep but 350mm in lenght and width. Been told to simply fill the hole with concrete and put a post bracket onto it, instead of using a post stirrup and stickm that into the wet concrete.

Any advise would be of great assistance. Sorry if i seem a little on the amateur side.

Before you worry about the facia lets start at the bottom. Your footing size is way too small. Minium specs would be 450X450X450 and 500 depth to bottom of hole

[ozizu]

Before you worry about the facia lets start at the bottom. Your footing size is way too small. Minium specs would be 450X450X450 and 500 depth to bottom of hole

i agree its the little on the shallow side but the mitre10 pergola brochure quotes a post footing dimension of 300*300 and 300 deep. But other internet resources quote anything from 250 to 900. Also want to go for the 90*90 posts since they look a little more smaller since my backyard is very small to say the least

[Tool-Horder]

i agree its the little on the shallow side but the mitre10 pergola brochure quotes a post footing dimension of 300*300 and 300 deep.

I just love a lot of these 'how to' brochures put out by various companies. I havn't read the brochure but by any chance are they talking about a true pergola with timber rafters only or rafters and batterns with no roof sheeting? Two majorly different structures as far as stresses and windloads go.

I dont know what your council requirements are down that way but a structure that size up here would require council approval and to meet the BCA regs. The footing is not just there to support the weight of the structure but in a situation like yours it is more to stop it flying away in the wind. Your neighbour may or maynot be happy when it lands in his yard .... guess it depends if it lands the right way up just where he needs it!

[Barry_White]

I've got to agree with Tool Horder on this. A pergola is a structure that has just beams and rafters with no roofing materials on it.

When it has a roof on it, it becomes a patio roof and comes under different stresses such as wind download and upload pressures and requires substantially larger footings. I don't know about Victoria but in NSW different councils have different requirements under their LEP's for exempt structures varying from 0m2 to 20m2.

[thebuildingsurv]

You will need a building permit my friend.

[ozizu]

I just love a lot of these 'how to' brochures put out by various companies. I havn't read the brochure but by any chance are they talking about a true pergola with timber rafters only or rafters and batterns with no roof sheeting? Two majorly different structures as far as stresses and windloads go.

I dont know what your council requirements are down that way but a structure that size up here would require council approval and to meet the BCA regs. The footing is not just there to support the weight of the structure but in a situation like yours it is more to stop it flying away in the wind. Your neighbour may or maynot be happy when it lands in his yard .... guess it depends if it lands the right way up just where he needs it!

I agree i will need a permit. Also the mitro10 brochure gives out dimensions for the post footings if later on down the track i cover it up with laserlite etc so I assume there pergola is safe and strong enough for coverage later on down the track.

However my situation with the footing is that i already have a partial footing in the hole i want to put the post because of the colourbond post. I have simply dug around it at the front of it to get my 350*350 wdith and length. Half of the hole has got concrete already. The existing concrete in there starts rought 150mm below my concrete level and also takes up half the hole size. So essentially i was hoping this would be helpful to me and would avoid the need to dig somewhere else since there is a stable concrete footing in already. I hope i have made myself clear.I can dig up somewhere else and get a depth of 450mm but i didnt want too many posts in my backyard and was hoping 300deep would do. Could i possible make the depth and width bigger to maybe 450mm to compensate for the lack of depth. Also smy soil is heavy clay which I thought would help me out further.

Also was at bunnings yesterday and seen these fascia brackets which bolt onto the rafter and then come down and turn 90 degrees to be flush witht the fascia. Are these brackets a better alternative to putting a piece of timber at the end of rafter to support a ledger acrooss the fascia?

[brynk]

how big is the gap between the roof tiles and the fascia? if the colourbond fascia is not directly fixed to the trusses then i would not put rafter connections onto it. i have seen metal sheet torn by wind-loads where other members have been fixed. forgive my next question, but i must clarify - you are looking at the fascia, yes? not the gutter?

if you are fixing your patio posts to the fence posts then provided it is done properly, the patio will be structurally tied to the fence & should be sufficiently strong, granted it is a decent run of fence that is. that's not to say that it will meet regs though - in all likelyhood it wont if the fence is a shared boundary. and building right to the boundary, in canberra anyway, will give you grief in some instances with approval if you already have built right up to a different boundary (you can only have one 'zero-setback boundary' and i would say this is the case in other jurisdictions). you are getting approval, right?

what are your post spacings? what type of timber are you using? what about for your rafters? where are you in the world? what about the beam supporting the rafters,what type & size of timber is this?

these are the questions you need to be able to answer before a determination can be made as to whether your footings are sufficient.

r's brynk

[silentC]

someone has suggested simply popriveting the joist hangers into the fascia and that would be safe as houses

I'd hate to live in their house then. Hopefully they were having a lend of you because if that was a serious suggestion, then they need a good kick up the backside.

Seriously, if someone told you that and you even considered it, then you're out of your depth with this and I'd suggest you pay someone to do it. Honestly...

[pawnhead]

I wouldn't even be confident fixing through the fascia into the existing rafters, as the eaves overhang is often at the maximum allowable, and isn't rated to carry the extra load of another roof.
Selected rafters could be stiffened by attaching cantilevered steel angles to them before attaching a ledger to pitch the new roof from.

[ozizu]

I want to put 5 posts of 350*350 at 300 deep which already have partial concrete in the hole with a post size of 90*90 pine. The post spacings will be 2.4mtres. Like I said earlier I can go wider and make the hole 450*450 and make sure the areas where there isnt that concrete bit is goes 450deep. The current colourbond fence is straight and the posts seem very secure.

The pergola i want to build is a 3metre by roughly 6 metre structure. It will be fully supported by the fascia connection on the 6 metre side. So width is only 3 metres. height to the fascia is about 2.5metres and the same goes for the post heights. The fascia ledger and the rafters were going to be 140*45 and the the main beams to be 190*45.

There is a 45mm gap between the end of the rafters inside the roof and the fascia flush, and yes im not talking about the gutter.

The fixtures I would like to install ontop of the pitch roof are mainly laserlite and any other light structures. I am doing a pitch roof because of my small minute backyard, I dont want a standard straight pergola roof since it will make the area look smaller. But i feel a pitch roof will make it look a little bigger and more roomy, better for air circulation also i hope.

The block has two single storey units with a common driveway for both. The pergola is on the front unit, and the current colourbond fence seperates my backyard and the thin landscaping and driveway. I know i will need permits from council but thats another story.

[silentC]

I think I'd be looking at hanging it off the wall. Or it could be free standing with an extra row of poles on the wall side.

[barned01]

when i did my pergola, i secured extra beams to my rafters using a bunch of bolts.
I then made my own bracket using 3mm steel (i think) that is based on the bunnings right angled one but was 3 times longer
.
i then pulled the metal facia off and secured a beam of wood against the rafters and then put the facia back on.
The tin facia is not a structural part of the house so it must be reinforced. (this method was approved by my council)

the other way you can do it is those brackets that extend past the facia and gutter and create a mounting point for a new strutural facia for your pergola.

As for the fence posts If you want to do it aesthetically pleasing and what not and you want to do it right, can't you remove the section of fence around the posts (please say you don't have a good neighbour fence), remove the post, crack the concrete off with a sledge hammer, make the hole bigger and then cement both fence post and pergola post in the same enlagrened hole to the proper specfications. the work required to do this by yourself would only add a day overall to your schedule of erecting the pergola.
this was my facia support plans i submitted:

this was my footing details i submitted:


note this may or may not be over engineered as i did not use an engineer to design my pergola, i designed it myself and thought if i designed it to maximum specs then it should be fine to be approved (it was).
the general dimensions were 5 metres by 6 metres pitch roof in RHS steel.

[barned01]

I think I'd be looking at hanging it off the wall. Or it could be free standing with an extra row of poles on the wall side.

I thought the external wall wasn't structural either....(although a damn sight stronger than the eaves i guess given it is already a downward force acting on it.)