Cavity Block Shed

TheP

Hi there.

I just bought 18"x9"x9" cavity blocks, the type with flat top and sides, 2 protruding groves on the bottom, and a hollow core, to build a shed. I assumed I lay them flat, onto the foundation/base, but a friend suggested they go vertical. Who is correct?

Also, I know how to build the corners by overlapping the courses, but how do I end each course for a doorway and window?

Thanks in advance.

RKQ

Lay them flat. The wall will be 9" width, laid in courses 9" high.

Set the doors and windows out to full block dimensions to limit the numbers of cut blocks! So a door or window will be at least 36.5 inches from a corner = 2 blocks + 1 joint.

TheP

Thanks RKQ.

Is there any impact from using cavity blocks for the shed? Maybe I'm listening to too many people, but someone else mentioned I'll get condensation on the inner walls. Its a small shed 4m x 3m, with a pitched roof, no heating needed.

Also, can anyone suggest where to get a teak door for it in Cork?

Thanks folks.

RKQ

A good render usually prevent moisture on Hollow 9" blocks.
You could also dry-line with insulation at a later stage.

Solid 9" blocks would allow water penetration easier unless well rendered.

It will depend on its use and what you are storing in it. Condensation can be a problem in all unheated sheds, at this time of year. Open the door regularly to lett the wind blow through and dry out any condensation.

Slig

TheP wrote: »

Thanks RKQ.

Is there any impact from using cavity blocks for the shed? Maybe I'm listening to too many people, but someone else mentioned I'll get condensation on the inner walls. Its a small shed 4m x 3m, with a pitched roof, no heating needed.

Also, can anyone suggest where to get a teak door for it in Cork?

Thanks folks.

Because the shed wont be heated and is in danger of being damp I would avoid using a timber door. They can swell and warp in damp conditions which leads to loads of problems, better going for PVC.

SpitfireIV

TheP wrote: »

Thanks RKQ.

Is there any impact from using cavity blocks for the shed? Maybe I'm listening to too many people, but someone else mentioned I'll get condensation on the inner walls. Its a small shed 4m x 3m, with a pitched roof, no heating needed.

Also, can anyone suggest where to get a teak door for it in Cork?

Thanks folks.

My 'workshop' (as i like to call it ) was constructed from 9" cavities approx 35 years ago! Its been a garage, a pigeon loft, a shed, and now my shop. It has no rendering, no plaster on the walls, has a thin shell of a concrete floor and its grand, no damp proof barriers! Seriously. On really wet days it might get a little bit damp inside but I can live with that. I put a stove in a few months back too so that helps keep the place grand and dry (and warm! ).

I'm in the process of putting an extension onto the back of it, I dont know if I'm gonna go the full hog with that, ie insulation and such, probably no point, use the original shed as inspiration

TheP

Yea, my father had one years ago, and the very odd time was there a drop of condensation in it, nothing major at all, which is why I'm happy to go with it. I'm going to put a 9" DPC between the first course and the concrete floor, get a teak door and frame and put a ride roof on it.

I have another query on laying the cavity blocks.

If I leave a gap of 800x2100mm for a door frame, the frame will be fixed onto the end of the cavity wall. But the cavity blocks will have a hole in the face, i.e. they are hollow. Should I finish the wall butting onto the door frame in a solid block or just fill the cavity holes on each course with cement?

Thanks chaps!

SpitfireIV

TheP, how I've worked around the issue of door/window openings is (and I hope this makes sense). When I started a row, I started at either end (which I believe is the correct way anyway, so you can string a line between the two), so, I layed a full block against the door/window opening to give me a nice flat, clean edge, and then layed a block at the opposite side of that lenght of wall and filled the row between these blocks, if it came to the point where a full cavity wouldnt fit (usually around the middle of the row somewhere) I'd put in a couple of filler blocks or cut a cavity.

Then for the next row I'd again start with a full block, but step it in half a blocks width, so that when I had that row complete I could chop a cavity block in half and use the clean, flat edge for the inside of the door/window opening.


Edit, after reading your question again I'm wondering if you mean you are asking about a fixing point for the door frame? Not sure what you mean by the cavity being on the 'face' of the block? ie something a little heavier and thicker to give a better anchor? If so, then all I've done to address this was ever third row or so, maybe fourth (cant remember (I'm putting in a big door) I started the row with a couple of filler blocks on end, that 'ought to do it.

TheP

Thanks CroppyBoy1798,

Thanks, makes perfect sense.

The first and end block of a straight run, on the same course, will have a hole in it. I wondered how to block this up - cement and then a good plaster coat?

My query around the door was again the above hole in the hollow cavity block, and how would the door frame be fixed onto the "hole" section. I've since learned that "Galvaband" can be used (may have this spelt wrong), where its pinned around the end block, the door frame fixed onto it, and then plastered into place, as is the door frame.

Thanks folks.

AleoN

TheP
You can purchase cavity blocks with a flat end for this purpose. You would normally order a few of these with your order of cavity blocks. You can also get half blocks in cavity as well which have the flat end. Hope this is what you mean.

AleoN

TheP

Thanks Aleon!

That is my solution.

That you all for your help!

ctrl-alt-delete

You could use solids around the door you mention above,

I always found it gives a nice place to get a fixing for the door.