decking "quote 224 posts" is that too much?

[moonlightandjj]

Hi
We didnt realise how much our garden slopped till we had our extension built lol. Now we has finished we need an deck.

I got a quote, the deck needs to be raised 50 cm so I can wheel myself straight out on to it ( see what I mean about the slooping garden - out frount it is only 4 inches difference lol). Anyway we sid if we are gonna have one might as well make it big enough to have a table and chairs etc on it.

The size we came up with is 4.84 (width of house) by 7.0. We were told that we would need over 224 posts as posts need to be every 400mm and we will need over 50 joist ( not inculding noggings), and obviously the boards and rails etc. The quote came in over 5 grand, which to me seems very expensive. or am I out of touch

I know we will need a lot of posts - but I wouldnt of thought it would be that many. Before my accident I made small raised decks but had posts every 1000 outside ( and corners lol) and 500 inside (deck was very small), just had couple of chairs on it.

Can anybody advice me, I dont want to be ripped off, and I get frustrated at not being able to do stuff any more.

Thanks in advance

Sharon

 

[WabbitPoo]

Without seeing the job I'd say, yes, you would be being ripped off. No way would you need posts every 40cm! It'd be like installing a huge solid cube of wood! even every metre is overkill, especially if you use 6x2 joists.

if you live near me I'd give you a free quote!

 

[^woody^]

Assuming you want the deck boards running paralell to the house, then its 12 joists at 450 centres, then is say 1m between posts then its 7 posts out so that 84 posts approx.

You would use the house the fix a wall plate to so no posts at that end. Also I would use deeper joists so can do longer spans, so less posts and less digging.

Seems a high quote to me

 

[Thermo]

way over the top in price (assuming its softwood) and the way it is designed. Get some more quotes.

 

[megawatt]

Thermo is correct, the deck needs to be designed properly to use posts, beams, joists with noggins and boards.

If you do it correctly you'll probably work around 4x4 or 6x6 posts, 10x2 or 8x2 beams and 6x2 joists and you'll need far less than 224 posts ... It'll be closer to 30 or so I'd say

My guess is that they've simply gone for posts everywhere with joists sat on the posts and no beams ... Nothing really wrong structurally but it's a lot or work and totally unneccessary.

MW

 

[Thermo]

way over designed and it leads you to the assumption that they dont really know what they are doing.

 

[megawatt]

Yup, I'd agree ... 224 holes and footings

I'd love to see a photo ... The OP's garden would look like the survey site for a new oilfield.

I'm surprised they didn't actually suggest building a 50cm dwarf wall around the perimeter, filling it full of aggregate and laying slabs

MW

 

[huw169]

I have just built a 4.8 by 2.1 m deck for 250quid - materials only. Gives you an idea of materials for size. Admitedly it was a floor mounted one in the end, but I designed it to be posted, but changed my mind last minute.
According to all the sites, 1.8m is the max distance between posts - 40cm is way to close!
It also took me about a day.
So i'll do it for 4k for ya - what a bargain!!!

 

[megawatt]

Post size, beam and joist spans vary considerably based on the sizes and species of the timber and its expected loading.

1.8m is the max distance between posts

No it ain't

There are many good sites where this is all explained in detail and tables provided to give spans.

Do a search on deck beam span or similar, you'll find loads.

I like this site as a generally good guide (it's American though so you need to use a little imagination in some areas) ...

http://www.decks.com

MW

 

[moonlightandjj]

Hi
Thanks for your replies. Funny you should mention about building a dwarf wall cos over the weekend we have talked and talked about nothing but this bloodly decking lol, the pros and cons etc.

We have realised that with decking it dont last long and it requres lots of maintenance - but can look good. But if we built a raised patio it will be a soild structure and wont require any maintaince, and we can build on the top half if we wanted to when the funds were there, i.e we could build either a bar /bbq area, have a spa. If we think about it properly and dig deep enough and put some insulation etc under concrete it would aslo be ready for conservatory should we decide to have one in the future etc. As the patio would be big enough for both.
And by going by the price of what it cost for the foundations (labour and price of materials) up to damp proof level of our extension, it wasnt that much. So perhaps we would be much better off going that way.

Thanks again for all your advice. I still think we will have a deck but a much smaller one but in the bottom of the garden, still slightly raised, but on a scale that we can - well hubby can build ..lol

Sharon

 

[megawatt]

That's one hell of a lot of backfill

 

[tonybhoy]

£65 per m2 including labour and materials is what I was quoted last summer.

I was doing a 67m2 raised deck.

Ended up doing it myself cost me about £2900 including labour of around £800.

I paid a joiner to set out the posts and start the whole thing off and I had a labourer digging out the post holes and other stuff like loading up the materials for about three days.

We fitted about 30 posts I seem to recall and used about 45 bags of postcrete which is amazing stuff BTW.

 

[vsynth]

Is this by any chance an example of the builders previous work?

http://en.wikipedia.org/wiki/Image:Woodhenge_4_DB.jpg

 

[Bankrupt]

In my experience the major problem with decking is RATS that invariably move in underneath it.....

 

[Thermo]

twaddle, unless there is a food source there