The aerated concrete cracked. What do I do now?

uno83 · 22 Nov 2011 at 11:18 PM

Matti_75 said:
Use programahylsa with lightweight concrete screw.

What is that, and where can you find them? I googled a bit but didn't find anything that seemed to match. Is it a frame screw of some special lightweight concrete variant?

SBH · 23 Nov 2011 at 2:50 PM

Foam expands in the frame, sometimes so much that you have no function in the leaf (window/door cannot be opened). Attach the sleeve to the frame first. Adjust, secure with screws. http://katalog.essve.se/webspeed/ka...t_bid=V70&dokid=wc396392&katnr=1&katsektnr=22

mycke_nu · 23 Nov 2011 at 4:20 PM

Spray foam works excellently, but you have to place a few wooden blocks across the doorway until the foam stops expanding.

Alfredo · 23 Nov 2011 at 4:29 PM

mycke_nu said:
Foam works excellently, but you have to put some pieces of wood across the doorway until the foam has stopped expanding.

Yes, it works, but it's important to do it right. Not a good idea to "overfill" everything and then watch as it expands, and expands, and expands.... :O

Matti_75 · 23 Nov 2011 at 4:32 PM

Use one of these screws for the frame sleeve that SBH linked to. Regarding the discussion on foam sealant, use a foam gun and a well-known brand and fill just the right amount. Absolutely no more than half the width of the gap. Sorry, the link doesn't insert too well on the iPad.

uno83 · 23 Nov 2011 at 11:03 PM

I've tried gluing the pieces with Sikabond AT now. The worst that can happen is that it doesn't hold, and I'll have to polish it up. I've also bought some clip nails (125 mm was the longest I found) and long nail plugs, we'll see which I go with. The guy in the store suggested I drill holes that are larger inside the wall, spray in anchor compound, and attach frame screws to it, but I think I'll try simpler methods first.

Eddi Thomason · 23 Nov 2011 at 11:09 PM

uno83 said:
I have tried gluing the pieces with Sikabond AT now. The worst that can happen is that it doesn't hold, and I have to polish it. I have also bought clip nails (125 mm was the longest I found) and long nail plugs, I'll see which I go for. The guy in the store suggested drilling larger holes inside the wall, injecting anchor compound, and securing with frame screws, but I think I'll try simpler methods first.

Instead, go with the excellent suggestions from SBH and Matti_75.
It IS nice to have the adjustability that frame screws/frame sleeves provide.
If you're worried when putting in the screw, you can always put a board on each side of the wall and tighten them with a clamp or two! But I actually don't think that's necessary.

uno83 · 23 Nov 2011 at 11:22 PM

My thought is that it might be enough to adjust one side (there's a wooden frame on the other side of the door opening) and just make sure to mount the lightweight concrete side straight.

I managed to get the picture of the screw. It looks like a smart option. However, the wall is very porous, and the screws weren't that long unless you go for very thick ones. No problem at all to drill into the wall with a regular high-speed steel drill, so I'm worried it will just crumble if you pull a bit on one of those screws...

EDIT:
I now see that I was looking at the concrete screw, and that there are lightweight concrete screws as well, which are significantly longer. If I use the mounting brackets, I might even be able to use the current holes in the frame... http://katalog.essve.se/webspeed/ka...t_bid=V70&dokid=wc433885&katnr=1&katsektnr=34

SBH · 24 Nov 2011 at 12:21 AM

preferably have adjusters on both sides. with foam, you don't get that.
after twenty minutes, I want to be done with door/window installation,
not installing braces and waiting for the foam to cure.

JanneL · 24 Nov 2011 at 12:58 AM

Why bother perforating the wall with all sorts of junk and maybe still not get it right. I assume your lightweight concrete wall is 70 mm, just like the door frame. If you email me your address, you'll receive 2 clip nails with the mail carrier the day after tomorrow, for free, length 160-170 mm. If you install the frame correctly, you probably won't need to adjust it later. That's necessary in a new construction, but this building has been standing for over half a century.

uno83 · 24 Nov 2011 at 9:52 AM

Yes, cleat nails actually held up for over 50 years with the old frame, so it might be just as well to go with something tried and true. With your two complemented with two 125 mm ones, it might work. It's not a particularly large gap either.

bjozac · 18 Apr 2013 at 7:42 AM

Found the thread when I was looking for ideas on fastening frames in my -57 blue concrete house where the walls crumble if you just look at them angrily.

There is a "new system" at k-rauta, where you buy a frame screw in 3 parts.
* Sleeve
* Pressure equalizing washer
* Lightweight concrete screw

Thread the sleeve into the back of the frame sides
Press in the washer so that you get a larger surface area against the wall stub
Adjust the sleeves until the door sits somewhat (it becomes difficult to achieve a 100% opening width when you can't press inward in any way).
When satisfied, gently insert the screws (~1-1.2dm) into the wall.

It went surprisingly smoothly, although I had to buy an L-torx since my bit holders didn't fit into the frame holes.
Expensive as hell, 1500:- for a set of about 100, there were also ones for 20 screws but I needed 24.

It's not as good as using wood studs, but it's better than drilling and plugging (for me).

anders07 · 18 Apr 2013 at 9:13 AM

bjozac said:
Found the thread while looking for ideas for attaching frames in my -57 blue concrete house, where the walls fall down just by looking at them angrily.

There is a "new system" at k-rauta, where you buy a three-part frame screw.
* Sleeve
* Pressure equalization washer
* Lightweight concrete screw

Thread the sleeve from the back on the frame sides
Press in the washer so that you get a larger surface area against the wall stump
Adjust the sleeves until the door sits somewhat (it becomes difficult to get the opening width to 100% since you can't press inward in any way).
When satisfied, carefully insert the screws (~1-1.2dm) into the wall.

It went surprisingly smoothly, although I had to buy an L-torx as my bit holders wouldn't fit into the frame holes.
Expensive as hell, 1500:- for a set of about 100, there was also for 20 screws, but I needed 24.

It's not as good as installing wooden studs, but it's better than drilling and plugging (for me).

Thanks for the tip!

I have the same trouble in our lightweight concrete paradise. So far, I've cut out the lightweight concrete and placed a stud fixed with plugs and gypsum plaster, then screwed the frames into that, but it's quite time-consuming (and dusty).

seniorkonsult · 18 Apr 2013 at 9:16 AM

You cannot adjust the frame, and if the house/wall moves, it will crack. It should especially not be used in exterior walls made of wood.
In a way, this is a masonry construction, so only the adjustment problem remains.

bjozac · 18 Apr 2013 at 9:33 AM

No, you can't adjust, but under the same conditions as in my case with a 7 cm wall, there is no chance in hell that you can insert a plug big enough to stay in place and big enough to handle a jamb screw without cracking the wall.

Aside from real jamb screws, to my knowledge, there is no construction with room for adjustment. If I turn it around and take, like many others with the same problem, the basic conditions with embedded nails in the wall, no adjustment has been needed for 60 years, and I consider the likelihood of the house moving enough to require adjustment now compared to 1957 to be minimal.

So with my own weighting of risk analysis and conditions, I completely removed the jamb screw from the list. What remained was k-rauta's system and nail/foam, which I considered to be the easiest.