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How to build a patio roof extension?

DIYH
Growing in Experience

How to build a patio roof extension?

Hi

I'd like to extend this patio roof with the blue guttering to provide a bigger area. 

What's the best way to do it? I'd like it to be sloping upwards and out over where the sleepers are so not to darken the back rooms even more. The extended area approx 2m in width will have more brick pavers on the ground. 

I'd also like to remove the middle support posts to have more area for a table and chairs, but not sure if that's possible. 

Thanks so much!

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EricL
Bunnings Team Member
Bunnings Team Member

Re: patio roof extension

Hello @DIYH 

 

Thank you for sharing the photo and outlining your plans, your outdoor space looks inviting, and extending the patio roof will definitely enhance it further. Since you’re aiming to expand the blue-guttered roof section by about 2 metres, sloping it upwards and outward over the area with the sleepers, the good news is this is absolutely possible, and there are ways to do it that preserve both light and usable space. However, before you begin, it’s essential to check with your local council in Roxburgh Park for any rules or permits required for modifying or extending patio structures, especially if the roofline or post configuration is changing.
 

Since your existing patio frame has already been constructed to take the weight of the current roofing and to withstand inclement weather, any extension must be designed to the same standard. Because you're planning structural changes including removing the middle support posts and altering the roofline, your best first step is to engage a licensed draftsperson or structural engineer. They can design a modified frame and foundation that accounts for the new span, especially since removing the central posts will require a reinforced beam (often a steel or laminated timber beam) that can safely handle the load.
 

To maintain natural light into the adjoining rooms while extending the roof, consider using polycarbonate roofing sheets like the Suntuf Sunlite available at Bunnings. These sheets come in clear or light-diffusing options, block UV, and are designed to let in light while keeping rain out perfect for an upward-sloping addition.
 

For structural framing, you’ll likely use galvanised steel patio beams and posts, or treated pine if your current structure is timber. The extended brick pavers can be laid once the new posts and footings are in place. Make sure any new foundations are engineered to match the load-bearing requirements of the extended frame. This is particularly important since the load shifts when you remove posts.

If you’re DIY-savvy and keen to be hands-on, you can complete parts of the project (like paving, painting, or polycarbonate sheeting), but any structural modifications especially involving post removal should be handled with professional guidance to ensure safety and compliance.
 

This is a great project that will definitely add functional space and value to your home. Just be sure to take the planning phase seriously, especially with council and engineering approval, so the final result is both beautiful and sound.

 

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

 

If you need further assistance, please let us know.

 

Eric

 

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Dave-1
Community Megastar

Re: patio roof extension

Good Evening @DIYH 

That will be a nice large area to entertain for sure! :smile:

As @EricL has said its doable and he mentions a bunch of things to consider and look into. 

 

An extra one is where the water from the extra 2m by XXm will go to, wether you have the new section tilted upwards or keep the same slope that the existing one has the drains/downpipes/guttering will be carrying more water. 

 

Instead of tilting the roof, id consider alsonite replacement of some existing panels, it can cut the UV but still allow light through, so that way the roofline will look the same but your overall light will increase.

 

As for removing the posts, I would definently talk to a builder as the load needs to be reassesed with strenthening posts plus a span support of some kind. Depending on the height of the existing roof you may run into issues with a wider support if your remove the center posts.

 

One last thing and it heads me towards an architech is that an extra 10sqm would be a large addition to a flat roof in regaurds to uplift in wind. You are going form a large sail to a huge potential sail so making sure its constructured correctly would be a wise move (especially insurance wis

 

Davee)

DIYH
Growing in Experience

Re: patio roof extension

Thanks for your help Eric and Dave!

With budget constraints I am going to shelve the idea of removing the posts for now and perhaps just solve the problem of the roof blocking light into the house .

I have seen on the website some options for polycarbonate roofing to replace a number of the solid panels . Please could you to tell me which options are best for letting light in but keeping heat out? 

Also good ways to install in order to prevent leaks?

Many thanks, this forum is great! 

 

Dave-1
Community Megastar

Re: patio roof extension

Afternoon @DIYH 

:smile: Yeah I do like this forum as well. I havnt installed any polycarbonate roofing tho have bough several different types over the years for student projects. I would actually go into your local bunnings  and have a gander at the types as up close will show you how dark they are and also you can factor in how much light they will let through (therefore heat) with their sun rating. You may want a horizontal blind idea if the area gets supper cool in winter so you can have the clearest polycabonite available. or go for more polycarbonite with a darker tint. I just had a look and there is a Beehive roofing style (corrorgated) that may suit your needs as it takes away the harshness of the sun. Suntuf 2400 x 860 x 18mm Solar Ice Beehive Polycarbonate Roofing 

 

Another way you could bring in light with less heat would to have some outside mirrors tilted to reflect the light into the area, I like this idea as its something you can change and it will also change seasonally. You could have the mirror as an outside panneled door, framed picture mirror depending on how much light you want. Hume 2040 x 820 x 40mm Entrance Door 10Lite Clear Glass is the idea type and if you kept an eye out on buy swap and sell social media sites you may find old ones that you can then paint with silver mirror backing.

 

Dave

DIYH
Growing in Experience

Re: patio roof extension

Thanks for your help Eric and Dave!

 

With budget constraints I am going to shelve the idea of removing the posts for now and perhaps just solve the problem of the roof blocking light into the house .

 

I have seen on the website some options for polycarbonate roofing to replace a number of the solid panels . Please could you to tell me which options are best for letting light in but keeping heat out? 

 

Also good ways to install in order to prevent leaks?

 

Many thanks, this forum is great! 

 

 

JacobZ
Bunnings Team Member
Bunnings Team Member

Re: patio roof extension

Hi @DIYH,

 

Like @Dave-1 has mentioned, the Suntuf Solar Ice Beehive Polycarbonate Roofing would be a good option that will let light in while diffusing it to reduce the heat.

 

Installation should follow the method outlined in this SUNTUF Polycarbonate Roofing DIY Installation Guide

 

Integrating it with existing roof panels may require alteration of the frame and creating custom flashings for junctions. Depending on what issues you run into, it might be best to consult a professional for their assistance.

 

Let me know if you have any further questions.

 

Jacob

 

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