Attaching moldings to lightweight concrete.

[Fairlane]

Hello,

I am going to install new moldings throughout the entire downstairs, where the walls are made of aerated concrete. I have a cheap nailer from Meec and a compressor and hose for this.
Is this something that can be used?
If yes, what nails do I need?
If no, what alternatives do I have? (I've considered gluing but can't really see how I can apply pressure to the moldings until the glue dries.)

 

[Fairlane]

I can partially answer my own question after having read the manual.

Do not fire the tool at hard materials. Do not attempt to fire the tool at hard or brittle materials such as concrete, steel, or tile.

Well, then it will probably be drilling, plugging, and screwing... Ugh, it's going to take time.

 

[icho]

Rent a nail gun to shoot stainless steel nails into concrete. Costs a couple of hundred for a weekend and is well worth it!

 

[KjellTimell]

To attach moldings in aerated concrete, it's "listspik" you should use. It holds incredibly well!

Example, available in most stores:
https://www.k-rauta.se/byggvaruhus/listspik-essve-fzb-vit-60mm-25-pack

 

[tommib]

To fasten in lightweight concrete, I agree with using finish nails but would add that if it’s porous, you probably need to glue as well. That way, the nails hold the trim in place until the glue has cured. Finish nails also take quite a long time...

 

[Fairlane]

The list nail might take a bit of time as well.
Renting a gun might be tempting.
The question is which one is faster.
I will try to get up around 50 lpm including sawing etc in one day preferably...

 

[epw]

List nail is really good and doesn't take long. Make sure to pre-drill the holes and twist the list nail so the wedge is set vertically to avoid splitting the baseboard. 50 lpm is no problem time-wise if you are somewhat handy.

 

[Fairlane]

ok, will test it.

Should one toenail the nails? I assume that a punch should be used to avoid leaving ugly marks on the molding.

Does this work or is it not for lightweight concrete?

https://www.hornbach.se/shop/Listsp...amaCh0SbwDQEAQYBSABEgLLyvD_BwE#artikeldetails

The price 80 pieces for 23:- is a bit more tempting than 25 pieces for 46 kronor...

 

[epw]

It should be conical so that it cuts well. Don't forget glue behind it. Use something that adheres immediately like Superfix or extremfix or similar. A punch is not needed if you have a fresh hammer that doesn't leave marks.

 

[epw]

https://bolist.se/produkt/listspik-vit-efz-60-mm-10-st/?article=7313178225285

 

[Fairlane]

An update on how the work has progressed.

I bought regular white moldings in sizes 69x12 and 43x12. I also bought Essve white-painted trim nails and listened to the salesperson who assured me that you didn't need to pre-drill the moldings if you used these nails. Result: The moldings cracked.

Ok, I went and pre-drilled with 3mm and the moldings cracked again. I pre-drilled with 4mm and the moldings cracked, and the hole from the drill was visible.

Then I took out my sturdy bolt cutter and simply cut the nails so they were about half as long. Together with glue and pre-drilling, it worked. It still ended with me drilling and plugging what was left (together with glue).

 

[RapidSledge]

An update on how the work has proceeded.

I bought regular white baseboards in size 69x12 and 43x12. I also bought Essve white lacquered brad nails and listened to the seller who assured me that I didn't need to pre-drill the baseboards if I used these nails. Result: The baseboards cracked.

Ok, I pre-drilled with 3mm and the baseboards cracked again. I pre-drilled with 4mm and the baseboards cracked, and the hole from the drill was visible.

Then I brought out my sturdy bolt cutters and simply cut the nails so they were about half as long. Together with glue and pre-drilling, it worked. It still ended with me drilling and plugging what was left (together with glue)

Glue, apply pressure using some longer boards that bend easily like a bow.

 

[epw]

An update on how the work has progressed.

I bought regular white baseboards in sizes 69x12 and 43x12. I also bought Essve white-painted trim nails and listened to the seller who assured that you didn't need to pre-drill the trim if you used these nails. Result: The trim cracked.

Ok, I pre-drilled with 3mm and the trim cracked again. I pre-drilled with 4mm and the trim cracked, plus the hole from the drill was visible.

Then I took out my hefty bolt cutters and simply cut the nails so they became about half as long. Together with glue and pre-drilling, it worked. It still ended up with me drilling and plugging what was left (together with glue)

Did you drive in the nail with the wedge positioned vertically or horizontally? My experience with trim nails is that they generally don't crack if you pre-drill and place the wedge with the points up and down and not from side to side. Then it's easy to split the wood.

 

[Fairlane]

I tried it both ways and it cracked regardless. I think that nail might be unnecessarily thick. When I cut it down to 3.5-4cm it went better.

 

[epw]

Okay, it might be due to the quality of the moulding. If there are many fibers running along the moulding, it obviously tends to crack to a greater extent.