Hello,
I am planning to renovate my patio. 7.6x4.5m.
Beam: I am thinking of laying 7 lecablocks (59*19*9) with about one block's spacing (which makes it about 7.6m).
On top of that, I will place 45x90 as beams.
A total of 3 beams with 180cm spacing and overhang 45cm (total 4.5m).
Joists approximately cc60 provide 13 pieces of 45x145.
Wood lath 28x120.
Is this okay? I would preferably like to avoid using posts. Am I using an excessive number of lecablocks?
How should I "prepare" under the lecablocks? The current base is mostly undisturbed soil since 1976.
Best regards, Magnus
I am planning to renovate my patio. 7.6x4.5m.
Beam: I am thinking of laying 7 lecablocks (59*19*9) with about one block's spacing (which makes it about 7.6m).
On top of that, I will place 45x90 as beams.
A total of 3 beams with 180cm spacing and overhang 45cm (total 4.5m).
Joists approximately cc60 provide 13 pieces of 45x145.
Wood lath 28x120.
Is this okay? I would preferably like to avoid using posts. Am I using an excessive number of lecablocks?
How should I "prepare" under the lecablocks? The current base is mostly undisturbed soil since 1976.
Best regards, Magnus
Hello,
It seems like these were trickier questions, or perhaps I have been a bit unclear...
If I ask like this then: If I am going to place lecablocks on a 30-year-old soil bed, how should I prepare the groundwork so that they remain as stable as possible?
Regards, Magnus
It seems like these were trickier questions, or perhaps I have been a bit unclear...
If I ask like this then: If I am going to place lecablocks on a 30-year-old soil bed, how should I prepare the groundwork so that they remain as stable as possible?
Regards, Magnus
You are absolutely right that it is tricky.
A few years of untouched land usually does not start moving under moderate loads.
So if you remove the organic surface layer (which tends to be softer and can decompose and collapse), you will quite likely have a base that does not move significantly under the pressure of a deck. Be careful and disturb the untouched soil underneath as little as possible, so it retains its compaction.
Then you have frost, no matter how well the ground bears weight, it is also subject to frost heave. Some grounds have very, very little frost heave, while others move a lot. What/how will it be a problem for you if the deck rises a few cm each winter?
Another problem is if your ground doesn't heave evenly over the entire area, then it will bend in your deck each winter.
I think these are questions that all deck builders wrestle with when they start out, and there are no definitive answers, as it always depends on fairly unknown ground conditions.
Sure, there are ways to guarantee a completely stable and immovable deck. But most are not willing to go that high, as they want acceptable results with as little effort and cost as possible.
Do you have someone nearby, who might have the same ground type, who has built a deck and can share their experiences with you?
A few years of untouched land usually does not start moving under moderate loads.
So if you remove the organic surface layer (which tends to be softer and can decompose and collapse), you will quite likely have a base that does not move significantly under the pressure of a deck. Be careful and disturb the untouched soil underneath as little as possible, so it retains its compaction.
Then you have frost, no matter how well the ground bears weight, it is also subject to frost heave. Some grounds have very, very little frost heave, while others move a lot. What/how will it be a problem for you if the deck rises a few cm each winter?
Another problem is if your ground doesn't heave evenly over the entire area, then it will bend in your deck each winter.
I think these are questions that all deck builders wrestle with when they start out, and there are no definitive answers, as it always depends on fairly unknown ground conditions.
Sure, there are ways to guarantee a completely stable and immovable deck. But most are not willing to go that high, as they want acceptable results with as little effort and cost as possible.
Do you have someone nearby, who might have the same ground type, who has built a deck and can share their experiences with you?
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Hello and thank you for your responses.
It sounds like I can get started. Since I have beams, the entire deck will likely be lifted evenly (the weight is distributed), and as I don't use the deck during the winter, 2cm shouldn't matter. But if it lifts 7cm, it wouldn't be so good. What's reasonable 20 miles north of Stockholm? Should I place some sand or gravel under the concrete blocks?
Regards, Magnus
It sounds like I can get started. Since I have beams, the entire deck will likely be lifted evenly (the weight is distributed), and as I don't use the deck during the winter, 2cm shouldn't matter. But if it lifts 7cm, it wouldn't be so good. What's reasonable 20 miles north of Stockholm? Should I place some sand or gravel under the concrete blocks?
Regards, Magnus
How much it lifts must depend on how waterlogged the ground is (a gravel ridge typically has no water in it, and clay has quite a bit of bound water) as well as the depth of frost in that location. I really have no idea how large frost heave can become.BlombergM said:
A little sand or gravel under it probably won't make any difference, unless you fill down to frost-free depth.
I'm no expert on this directly, just so you know. But as long as no one contradicts me, I might be right.
Hi, put in a little more work on the foundation and cast pillars to a depth so that the frost cannot lift the pillars. You can insulate with ground slabs so you don't need to dig as deep, a good foundation is essential.
