Steel lintel, steel beam insulation?

Hello and good morning,

an opening in a secondary building wall is to be enlarged to 4m clear width and 2.125m clear height for a garage sectional door, or it already exists. Here an IPE450 (!) comes into play. The attached sketch shows the situation somewhat more clearly – although unfortunately it is not to scale. The web of the IPE is actually much higher and the flange comparatively quite short, so the illustration is somewhat misleading. The exterior and interior will then be plastered over. Inside, however, the frame of the door must be fastened at the top.

My questions:
With what and how should I best insulate the beam?
Exclusively gluing (e.g. XPS) seems somewhat daring to me, especially underneath (overhead) the beam. Screwing would certainly be better, but how can I then possibly deal with thermal bridges?
Against what could I fasten or screw the frame of the door?

Many thanks for your ideas.

Hello,

the IPE 450 seems to be appropriately dimensioned, it depends on the loads (wall height, how many N/m² live load on the ceiling are calculated, etc.). So that fits so far.

To clad such a steel lintel, it almost always comes down to the same construction: angles are welded on the top and bottom, inside and outside, in the size range 50x5 or 60x6mm. Between the angles, mineral wool is filled in and OSB boards or plasterboard are screwed to the inside of the angles. Exterior plaster carrier boards and plaster as desired.

I would proceed similarly on the underside. Build up a mounting level for the plaster carrier board, insulate and plaster. Although it makes me wonder why so much attention is paid to minimal thermal bridges through screws in a 24cm wall. I would not give it too much priority because it does not have a significant impact in calculations.

What exactly is supposed to be attached to your gate lintel at the top? A standard sectional door only has its sealing lip at the top, which must/should lie inward. All loads are transferred via the side guide rails directly down to the floor slab. Unless we are talking about an industrial door with an overhead spring shaft?? However, the gate size mentioned above speaks against that.

Is the space requirement for a normal deflection sufficient, or do you need a low headroom fitting?

Best regards
Simon

Hello Simon,

thank you very much for your detailed answer.
The beam has been officially statically designed, as far as that's okay.

Currently, the described room is to be used as a garage. Directly above it, a small residential unit is to be built "someday," and since I am currently installing the lintel completely new, I would consider a solid structural thermal insulation. Maybe the garage will be repurposed again at some point...

The sectional door from a large German manufacturer will be a so-called thermal variant, in order to also lay a good foundation regarding thermal insulation. Dimensions are 4x2.125m with N fitting and existing torsion spring. Regarding the number of fastening points for the lintel cover, I am unfortunately uncertain. Both the fastening of the cover and the drive chain would have to be done securely and power-fit on the steel lintel. Here, a welded angle bracket is suggested to me.

Regarding insulation, I have meanwhile the following layman's idea:
Fill the beams on the left and right of the web with XPS (90mm – sufficiently pressure-resistant given the height of the IPE) up to the flange edge (with mounting adhesive). Also below the beam up to the garage lintel cover. Then glue construction boards flat inside and outside. Then additionally screw expanded metal on the ceiling of the upper floor, close to the transition to the IPE, inside and outside, and pull it once around the beam. This would ensure that the insulation below the lintel is not held exclusively by the adhesive. Then plaster, first setting corner angles with mesh or corner plaster strips.
Additionally, to serve as a stop for the garage lintel cover and for screwing (as mentioned above), smaller welded metal angles should be provided.

What do you think about that? (seems more elaborate than your suggestion..?)

Best regards