Tony K

Thanks all, much appreciated. Now to go and drill two holes through a dense concrete block wall!

So perhaps a simple vent on one wall and a dMEV on the opposite wall?

I do intend for it to be pretty airtight. Would that change your advice?

Would you say a dMEV is noisy?

Morning. I've built a tiny little garden office in my SB. It's single skin blockwork, and will have 100mm pir insulation internally. It will be clad externally in such a way that will prevent rainwater reaching the blocks. As such, I only need ventilation sufficient to address internal conditions. I will work there most days and there will be a small heater for the winter months. There are no windows, only glazed double doors. They do not have trickle vents. It will be fitted out with bookshelves and suchlike. There is no water in there, no kettle, no WC. Advice has ranged from (at one extreme) just opening the door to enter and leave will give sufficient air changes, to (at the other extreme) mechanical ventilation is an absolute must. I have considered fitting simple vents to the front and back walls to allow cross ventilation. Bit of a pain to bore through the concrete blocks but not Impossible. Or, perhaps a roof vent of some sort might work, though I presume that would be mechanical. How would you vent it, if at all? Ta

Evening all. As the thread title suggests, I am planning to lay a mix of patios and paths in the garden of my SB. As part of achieving the necessary levels for the house itself, the courtyard garden was excavated down to subsoil level, which in my case means thick clay. Not sure if the photo shows it clearly, but the clay is fully exposed throughout, there isn't a pinch of soil to be found anywhere! I plan to compact about 100mm of MOT type 1 and 2 subbase, then use normal 5:1 mix on top, then lay slabs having back-buttered them with adhesive. In other words, I'll just do the normal thing. My question is, should I not be doing something else, too? Is the normal method sufficient given the ground conditions? Ta

So you think ties of some description are necessary then?

Evening all. This weekend I'm going to lay the reclaimed bricks you see below along the face of the blockwork wall. I've laid some blocks on their sides in front of the wall, as you can see. The bricks will be laid on top of those blocks, fairly tight to the block wall. It'll add up to about five or six courses. You can see that I've forgotten to include any ties when I laid the block wall. Does that matter for such a low wall? Should I try and put some ties in now? Ultimately I'll add coping slabs across the top of the bricks and blocks which will add stability, I presume. Cheers

You might be right @JohnMo, that's why I'm asking!

I was going to build an enclosure around the ASHP and paint the walls black before applying the protective paint. One reason for thinking about ivy is that it gives such good coverage that the wall would barely be seen anyway. That's why I haven't rendered it.

For context, this is the courtyard garden of my SB. The wall on the right is the one I am thinking of treating with the paint, mesh, and ivy. You can see that I've rendered around the windows so that the areas the mesh will not cover are presentable.

Thanks all. Just to reiterate, I'm not thinking of just growing ivy on the wall of the house. I am thinking about painting the wall of the house in a silane-based, nanoparticle paint, as per the spec in my original post, affixing metal mesh proud of the wall, and growing ivy on the mesh. I am aware if the need this will generate for me to trim the face of the ivy yearly and to cut it back at the edges. My uncertainty is over whether this paint can actually prevent the plant from attaching itself to the building as advertised. I have considered various other climbers instead but, even though some flower beautifully in summer, many die back in winter. I'd be looking at a bare wall half the year. Or, they seem to grow quite slowly.

Thanks @JohnMo and @saveasteading. The wall in question rises up to a parapet above a flat roof, so I don't need to worry about ivy getting into a loft. In fact, it would be pretty easy to trim at the top if needed. I had thought about honeysuckle or other climbers, but few of them are evergreen like Ivy, nor are they as quick growing. Are neither of you convinced by this arrangement of mesh sitting proud of a wall protected by this magic paint?!

Its not evident from the photos, but the roof runs to a gutter at the rear. I know what you mean about GRP vs Rubber, but for a garden building I think I'm pretty comfortable with rubber. I might even put a simple green roof on it to prevent crow attacks!

Now that, is a good point!