Low-level deck

[jinugu]

Help required experts.

I am attaching herewith a drawing (very crude) with what I was proposing (Drawing is not to scale & none of the timber will touch the floor except the posts). I want a low level deck (to avoid steps/avoid stumbling). I haven't provided the ground clearance etc because it's is flexible. I have seen else where in this workgroup that the deck will be classified as low level if its within 400 mm from the ground.

Some additional information :

1. External frame : 150 X 55 Treated timber. Fixed to the posts p1-p10. The external frame would not be touching he ground i.e will be screwed /nailed accordingly to the post. 

2. Bearer 1 will be fixed to the post at p1,p5 & p6, bearer 3 to post at p2, p12 & p7 and so forth.

3. Bearer 2 will be fixed to the post p11 (also intend to use angle bracket for additional strength) and the ends to the external frames on joist hangers j1 & j2. Bearer 4 to post 13 and the ends to external frame j3 & j4. 

4. May use noggins for support between the bearers for eg B1 & B2 and so on and so forth.

Any help will be very much appreciated.

Regards

Ravi

[EricL]

Hi @jinugu

It is important to level the area first if you're planning on using the DEKO 250 x 150 x 150mm Instant Concrete Foundation Block.

I recommend using joist hangers as it provides better overall support for the joist. When choosing your timber, please remember that it has to be rated for framing/outdoor use. A rating of H3.2 is sufficient for your needs.

If we measure the DEKO foundation block you'll see that it is 150mm tall. But when the timber sits inside the gap the actual height is only 110mm. So if we add the actual height of the DEKO and the 90x45 you will get an overall height of 200mm. But the actual gap from the bottom of the timber to the soil is only 110mm. If you are using standard 90 x 19mm L/M Decking Merbau SpecRite Pre Oiled KD Select the overall height of your deck will be 219mm. Anything you add under the DEKO Foundation Block will make the deck go higher.

Here is the link to the DEKO block: Deko Instant Foundation Block      

If you need further assistance, please let us know.

Eric

[jinugu]

Hi Eric

Thanks for the reply. I don't intend to use Deko, i had rather stick to the posts (and digging) which i am a bit familiar with. Levelling the area itself would be a bigger task for me. Thanks for the info on rating of timber. With the design that Mitchell has proposed, there is no place for me to put the joist hangers (assuming that I will have to screw/nail the posts to the joists ) . That's what it appears to me. Would you be able to give me an idea of how I could use joist under these circumstances?

Regards

Ravi Jinugu

[EricL]

Hi @jinugu

I've placed a picture of a joist hanger below and how it is attached to the frame.

If you need further assistance, please let me know.

Eric

 

[jinugu]

Hi Eric Sorry for the barrage of questions. Pls have a look at the the image I had attached. With the joists screwed to posts, where and how do i put the joist hangers. Thanks

[EricL]

Hi @jinugu

Your right, there is no space for the joist hangers. From my understanding the footing can be moved back a bit so that you will have space for the joist hangers. Let me just double check this with @MitchellMc when he comes back. As soon as I have more information, I'll get back to you. 

Eric

[MitchellMc]

@jinugu,

As @EricL mentioned, you can set the post back slightly from the frame to allow the installation of joist hangers.

Mitchell

[jinugu]

Thanks Mitchell. Appreciate your help. I am sure I will have more questions. Thanks once again. 

[jinugu]

Hi Mitchel/Eric

I must say you guys are very patient. One more question. When you say 'back slightly from the frame", would it be

1.  where the green square is shown i.e a little bit to the right of the joist hanger and so will still support the frame? or partly on top of the joist hanger?

2. or is it where the purple arrow is shown in the image below ( i am sure it won't be this option since in this case the post will not be supporting the frame at all)

A small pic will really help me. many thanks for your help.

p.s in any case the joists will be supported by the posts in the middle (i.e other than the ones attached to the frame) as shown in the image below

[EricL]

Hi @jinugu

It is on the purple arrow and not on the green square. Support must be given to the joist as it carries all the weight. Depending on the type of post you are using, the example I've drawn up is with a 90 x 90 post. Have a look at the sketch and if you have any other questions, don't hesitate to post them.

If you need further assistance, please let us know.  

Eric

[jinugu]

Thanks Eric. From the image I can see that the post is cut to let the joist sit on it. Will it work if I just attach them together without the cut - still nailed to the joust though.