do they stack if so i what order? im having a real problem of my techmarine taking something from 2 to absurd in the extremely fast.

Arguyle said:

Yes, they would stack as there is nothing saying they don't. Their order is based on what order the Techmarine uses. Keep in mind that Improve Cover is a Full Action and Evaluate is a Half Action, so the Techmarine can't do both in a single round.

Also, remember that the GM has final say and should keep things within reason. A flimsy, crumbling piece of debris shouldn't suddenly have better armor than a tank because the Techmarine spends a few seconds working on it.

Whenever I tell my GM that I'm about to improve some cover his first question is usually, how?

It's stopped me in my tracks a few times, lol.

Repair cement, everyone starts with it and its super durable.

With the repair cement, you may state that you attempt to reinforce cover/ use spot to build a sturdy defence structure.

However, do DMs require players to expend some repair cement or other materials in addition to the turns spent as cost to activate said speciality? I mean its the same as the Apothecary who reduces the amount of corruption and the Psyker that uses a Psychic technique right?

In our game it didn't cost any special materials.

The techmarine just had the ability to build solid cover fast. Always asuming that there is anything to build it from.

But as we never had the problem of standing in the desert with nothing but sand as far as one can look that was never a limitation.

How about this (not to be taken too serious):

Guardsman: Sir, your techmarine battle brother is really good a building cover. Thanks in advance.
Devastator: He sure has a knack for it. Often saved my ass.
Guardsman: Hey, where did that burned out chimera wreck disappear to?

Things like repair cement and bullets you have an unlimited supply unless the adventure specifically calls for a limited supply in which case your GM should tell you in advance.

Umbranus said:

I would have turned the sand to glass with a flamer and which gives a cover of 1, and then hardened it with repair cement.....

There is always a way.