How to remove concrete front porch and replace with timber decking?

[tmurrayrust]

Hi Folks,

I'm planning to replace my current very dated concrete/tile front porch (images below) with timber, and looking for some advice, so hoping someone here might be able to help. 

I've read lots of articles on BW about building decks over concrete - however, most of them have enough clearance to build directly on the concrete, using either plastic footings or angle brackets. In our case, it looks like the porch was originally built by pouring a raised section of the concrete slab (approx 80 mm high) and then sticking tiles directly onto it, and painting the sides. Therefore in order to get enough clearance to put joists in, I'm assuming the current concrete footing will need to be removed, most likely with a jack hammer.

The main questions I have:

1 - Is there a way to remove just the tiles and affix decking boards using the concrete as a footing? (I'm guessing this is very unlikely)

2 - If the concrete does need to come out, do I just need to take off the existing 80mm, or should I take out more to leave additional clearance? (the smallest joist dimensions I have seen in the guides are 70 x 35, so 80 mm wouldn't leave enough clearance for joists, plus decking boards) 

3 - Is there a way to remove the concrete that will leave it flat/even enough to use as a base for the joists, without damaging the rest of the surrounding concrete?

(3b - If not, would I need to use something like Lanko 173 Floor Leveller to get an even surface to lay joists on, and will that be suitable for affixing into e.g. with Dynabolts etc? Or will the jackhammered surface need to be levelled off by grinding with a diamond concrete grinding disc?)

In terms of my DIY ability, I'd probably rate myself as intermediate - I've done plenty of small improvements over several years, including building a deck in the backyard, and have previously removed a concrete path in the backyard using a jackhammer. 

[Akanksha]

Welcome to the Bunnings Workshop community, @tmurrayrust. We're delighted to have you join us and trust you'll find our site a handy resource for all your home improvement and garden projects.

Thank you for your question. Our resident Bunnings D.I.Y. expert @MitchellMc will be happy to provide some advice for renovating your front porch as soon as he can. Let me also tag our ever-helpful members @Jewelleryrescue, @RosieD, @JRRed and @Nailbag in case they have any thoughts. 

Thank you for your patience. In the meantime, don't hesitate to let me know if you need a hand getting the most out of the site.

Akanksha

[Jewelleryrescue]

Hi @tmurrayrust

Decks are a bunch of maintenance  and risk  of wood rot and other pit falls  then theres your issue of demolition .

How  about you simply  tile some beautiful natural looking wood like tiles over the top of the existing tiles .

I  Challenge you to research  whats avaliable.    

No maintinance ever.....  Your medium  skill set  will nail the job.

[Dave-1]

Good Evening @tmurrayrust 

An interesting puzzle you have. 

I have a few questions that might help you decide how to go.

1 - Is there a way to remove just the tiles and affix decking boards using the concrete as a footing? (I'm guessing this is very unlikely) 

A- Id say not worth the effort as the tiles plus grout will be maybe 10mm thick.

2 - If the concrete does need to come out, do I just need to take off the existing 80mm, or should I take out more to leave additional clearance? (the smallest joist dimensions I have seen in the guides are 70 x 35, so 80 mm wouldn't leave enough clearance for joists, plus decking boards) 

A- That 80mm isnt a lot of space to build a deck especially with the door just above. (After going through  just now looking projects id have to say maybe but with limitations)

3 - Is there a way to remove the concrete that will leave it flat/even enough to use as a base for the joists, without damaging the rest of the surrounding concrete?

A- I suspect you could remove that patio slab but still may not get where you want to be. I would be hoping that they have laid that footing straight on the concrete path, Thats why I want to know what is behind that timber looking strip?

(3b - If not, would I need to use something like Lanko 173 Floor Leveller to get an even surface to lay joists on, and will that be suitable for affixing into e.g. with Dynabolts etc? Or will the jackhammered surface need to be levelled off by grinding with a diamond concrete grinding disc?)

A- You could use brackets to support the joists so this wouldnt be necessary.

Questions for you

1 - On the second pic is that a piece of timber across the width? Any chance you could remove it to see whats behind it? As in a concrete slab or fill?

2- Have you thought of using something like RUNNEN Floor decking, outdoor, brown stained ? It is from IKEA But it looks like it could do the job.

When I was having a look around to see what you could do I came across these two discussions that may help you with a low deck idea.

Low-level deck over concrete and How to build a low-level deck 

Dave

[tmurrayrust]

Hi @Dave-1,

Thanks for the reply and working through my questions - very helpful! To answer yours:

1 - Unfortunately that isn’t a timber board running along the front that can be removed, it is an exposed edge of the concrete footing that has been painted reddish/brown 

2 - That’s a nice suggestion, it could potentially be a solution to my question 1 above but using an engineered click in place option rather than timber. I had a look and those units have a listed thickness of 2 cm, so if I removed the existing tiles that would free up about 10 mm, so they might just fit on the existing concrete without any need to remove any of it. 

 

Update - I spoke to a guy in Kennards about jackhammer rental and showed him pic 1 from the original post. He recommended to consult a concreter to make sure that any jack hammering would not affect the adjacent brickwork. So I’ll be following up on that to get a professional opinion about whether it’s even possible to get rid of the concrete without compromising any of the walls on the front of my house. 

 

Cheers, Tom

[tmurrayrust]

Hi jewelleryrescue,

Thanks for the response and your suggestion for keeping the existing concrete and replacing the tiles on it for something else. Depending on whether the concrete can be removed or not, this may be something we look into down the track - if so the. Dave1 has given me a nice starting point!

Cheers, Tom

[MitchellMc]

Glad to see our members have pointed you in the right direction @tmurrayrust. Please keep us updated and reach out again if you need further assistance after having the area assessed.

Mitchell

[Jewelleryrescue]

Hi @tmurrayrust 

That electrical  conduit going into the concrete would be  the most breakable thing.

To my construction  eyes I am seeing a house  built of bricks and the slabs and porch added last flush to the brick wall post build and should ealily come away from the wall.  I would have  used steel reo pins into the house foundation to support  slabs, But  if you discover they installed  angle grinder  will cut them  with ease.

Only get a medium to light jack hammer you can handle the weight of as you need   control is the key to an easy job.

Aslo invest in a rotary hammer drill for fine work  as it can be used as a cement chisel. can  easy go into 200mm concrete. with a chisel bit/

[tmurrayrust]

Hi Jewelleryrescue,

Thanks for the follow up - the conduit is for an old Telstra cable, and we dont have a landline any more, so if it breaks then no major harm done. 

Yes agree its likely the front porch was built after the brick walls - though what I can't tell is whether the driveway was poured first, and the porch on top (in which case it should leave a relatively even surface when jack hammered out) or if the whole thing was poured in the one go. If the latter then it may be a bit rougher and might need fixing up a bit before installing any joists. Either way, it won't be 100% clear until I get stuck into it...

Yes the plan is to get a medium weight JH, and fortunately I already have a Makita rotary hammer which should allow for more control when removing both the tile layer and any concrete close to the brickwork.

Thanks again for the input!

TMR

[Jewelleryrescue]

Hi @tmurrayrust

I hear you re old telstra land line.  I would  preserve that  telstra pipe just in case as Future fibre optics has to physically get to your house one day possibly. and they might just be using same conduit. Other wise they will have to dig whole new line in .  But 5G is supposed to be coming so 50/50 on its continued use.

I hear you  re drive and step  poured  possibly at the same time I would be highly surprised if they did.  But you can  rough break up the concrete   deeper than  required and pour a nice leveling layer for new work to sit on     as you said  not a huge area.

Ihope it all works the way you want,