building a shed

[spx]

hi, I'm about to build a shed at the bottom of my garden. A couple of my neibours have them but say they are quite damp.

I don't feel confident to build a double skin wall - does anyone know if I build the shed with the blocks layed flat will the water be able to penetrate through 9" of block?

I'll be using standard concrete blocks 4" thick 9" high.

Thanks.

 

[woodburyboy]

I'm towards the end of building a shed/workshop myself, out of block at the bottom of my garden. I've used dense block and intend to render it afterwards, but including a water repelant additive in the mortar mix. Paint the render with a good quality exterior paint and I'm sure that will stop the damp. The alternative is to use plastic sheeting on the exterior wall with either ship-lap or feathered boards - treated. Make sure the structure is more than 5m away from your house and is less than 30sqm otherwise planning permission AND building regs kick in...

 

[TexMex]

Don't forget a Damp proof membrane in the concrete base and put a roof on it (to keep the rain out ) also include a vent.

You'll find you will need a lot less blocks if you lay them the right way up (it'll be quicker too). Dry lining afterwards (if it needs it) would probably be a more effective and cost less (both in terms of money and time) than the blocks you'd save. It's also an option that you can add later.

 

[spx]

thanks for the reply guys. The only thing that I forgot to mention is that the shed will be built at the bottom of my garden which is on a considerable slope.

I was going to section off the area where the shed will be built an straighten the garden out. Some of the shed will be below ground level (this is also what my neighbours have done). Will a damp proof membrane and rendering stop water from seeping through?

 

[masona]

Some of the shed will be below ground level (this is also what my neighbours have done). Will a damp proof membrane and rendering stop water from seeping through?

Can you do a rough drawing ?

 

[spx]

Masona - don't spose you could advise how I put a drawing on here?

Been trying for ages to no avail!

 

[breezer]

Masona - don't spose you could advise how I put a drawing on here?

Been trying for ages to no avail!

there is help for you in forum information

 

[TexMex]

The only thing that I forgot to mention is that the shed will be built at the bottom of my garden which is on a considerable slope.

and according to your other post built on top of a dodgy retaining wall with a twenty foot drop. This gets scarier by the minute

Under these circumstances, definately use them blocks the right way up. It'll be lighter. That's if you decide to procede. I didn't answer your other post as it scares me too.

 

[spx]

Ha ha cheers tex.

Yer after a lot of thought I've decided to build it in the middle of the garden instead. Perhaps I could build one of those geezaboo japanese things down there instead............

 

[TexMex]

Probably just as well, it was the cracking (including the base) that really worried me. tends to indicate that there is a bit of movement going on there already. Putting even more weight on it could accelerate that quite a bit.

So do you have some dimentions in mind?
Will it still be on a slope?
If so, what is the difference in heigh of the ground level on the high side compared to the low side? Would this go across the width or the length?

What are you wanting to use it for? (office type could do with thermal insulation, Noisy workshop type stuff could do with sound issolation)

Questions, questions. Nosey oik aint I?

 

[spx]

Hi tex,

It will still be on a slope approx 1m down on the low side. Was hoping to straighten out the garden against it and put a lawn down.

It's going to be 4m x 3m and which is 1m off the width of my garden. I was planning on building it approx 2.3m high I'm sure this will be ok as it is 5m from the house.

Thinking of building it on 8" of redimix foundation concrete what do you think? (large pad rather than footings).

Was going to use it as a workshop but now the woman want's to use it as a gym as well. That's why I was concerned about the damp - end spending money on equipment and she wouldn't set foot in it if she found a spider!

 

[TexMex]

Oh dear.
The main problem I can see here is that drop of 1m. This creates several problems.

1. there's the mass of soil to be held back, which means a beefier structure.

2. There's going to be a mass of water heading your way on wet summer days. If you don't block this, the interior is going to get damp (like your neighbours). If you do block it, you could end up with a wallow outside the shed window.

3. Since the ground level outside the shed would be about 1m higher than the floor of the shed, you would have to either, climb in through a window or put the entrance on the back side of the building. This would not only be an inconvenience it would also be a security risk. Light fingered types feel more confident when they are not visible from the house.

A possible solution to this would be to introduce a seperate retaining wall just before the shed. So if you can imagine, you would approach the shed by going down some steps that cut through the retaining wall. At the bottom of the steps you would have a paved area (say 1m wide), that runs across this face of the shed. The shed would then have a door that opens onto this area.

The retaining wall would itself, have to be quite substantial. At 1m it would need to be about 13inch thick. You could then have drainage built into the bottom of this, that would run off onto the paved area. The paved area would be laid to a fall so that the water runs harmlessly around the shed.

Building the shed would then be a simple afair.

This would of course escalate the costs quite considerably. By too much?

 

[big-all]

heeelllooo

im no builder

could the solution not be to build a small retaining wall
behind and in front thus averaging it out and no
spoil to worry about

big all

 

[TexMex]

Could be, or any combination. Could just have the one retaining wall at the back (so the front of the shed comes up to ground level at the front). A retaining wall on the down slope, though, would have to be even more substantial, as it would have to retain the weight of the shed on top.

 

[spx]

I was thinking of thickening up the front wall of the shed so it acts a retaining wall but yer it would be a better idea to build it seperatly just infront of the shed. would certainly stop the damp.

I suppose I was just looking at what everyone else had done and foolishly copying!

One more question for you tex, there is a wall between myself and the neighbour it is about 6ft high, I don't really think he'll go for me building it up and using it as part of the shed.

Would you build right next to it knowing that you are unable to render that part of the shed or come in 2 foot so you can get behind to render?