Rainscreen with a drainage/ventilation cavity behind it. The wall needs to resist rain that gets driven in by wind and the water that does get in needs to be allowed to escape and not allowed to stay in the wall or travel to the interior. Overhangs help too. 

Overhangs are practical and can be very sexy if designed in a clever way. 

That looks like mould caused by wind-driven rain and poor stucco quality. It could also be due to vapours moving from the inside to the outside then causing mould to develop on poor qualty stucco; What's is the exterior wall construction? Is it insulated or not?

There are a number of companies in Europe who do stucco/insulation walls; STO, Ceresit, Isover, Weber, Baumit, BASF, Reelih, Samoborka, Roefix, etc.....

Their products usually have a mould inhibiting finishes or paints that are applied over the stucco. Those paints also have mould inhibiting properties. Apply stucco/insulation from one of those companies. Roof overhangs help, but they will not stop wind driven rain.

If possible, build the exterior walls from Weinerberger brick or Ytong blocks, then apply insulation and stucco to the exterior. I think both are available in Ukraine - contact their representatives. 

Can you do a rainscreen? Sure, it's probably one of the quickest and easiest approaches to control wind-driven rain regardless of the backup wall construction.

Do you need to do a rainscreen? No. I'm assuming a concrete or masonry backup wall for your structure and a stucco (not EIFS) finish. 

Mass backup walls with a direct-applied stucco cladding can easily be used without some type of rainscreen approach. Trick is to keep as much moisture off the walls as you can. Roof overhangs are a important tool in doing that, but they don't have to be huge. Parapet caps, corbels, drip edges at lintels, floor lines, window heads and sills, etc. all work to get wind-driven rain away from the building as quickly as possible. Look toward traditional mass masonry buildings for what works and what doesn't. They've been around much longer than any modern rainscreen approach. The key is being able to allow the wall to dry out sufficiently enough between periods of wetting that wetting doesn't overwhelm drying, and moisture doesn't accumulate in the construction. The wetter the climate, the less opportunity for drying, and the more water you have to keep off the wall.

There are some other tools to help keep water out of the wall assembly when you can't keep all the wind-driven rain off of it. Paint is one that is used quite commonly. The paint film sheds the water before it has a chance to be absorbed into the stucco. Water repellents are another. Polymer-modified stucco finishes are another. I've worked on designs of buildings using mass walls and each of those approaches and haven't had any issues yet. Keep in mind, these all need to be maintained (reapplied and repaired if damaged), but they do a good job at keeping water out of the wall assembly. It is very important that they are vapor permeable so as not to inhibit drying so that water that does get into the wall assembly can dry outward. You don't generally want them drying inward.

To do that, you'll need to control air movement, vapor movement, and provide thermal comfort for the interior without expending a lot of energy in heating each winter? Drafty buildings work great to keep the structure dry because you're constantly drying things out with air movement through the wall assembly, but are terrible for heating bills and thermal comfort. There are a lot of good sources of information for how to insulate mass wall buildings and controlling for air and vapor as well.

TL;DR ... if you want to do a rainscreen, that's great. But you don't need to. If you don't use a rainscreen, use a construction type that isn't moisture sensitive, keep as much rain off the walls as possible, and make sure you know how to control for air, vapor, and thermal comfort for the interior.

Chad Miller,

What's the deflection of a 300mm or 450mm thick Weinerberger (or Nexe) masonry wall fully supported at the bottom and at the top that spans about 10m meters in length on an average and maybe 2.8 meters in height?

What's the deflection on a 2x4 stud wall or even a 2x6 of the same length and height? Same for steel studs?

No matter whether you use the L/360 or L/720, the deflection in studs will be much greater than anything or solid masonry walls.

See where I'm coming from?

EIFS got a bad wrap in USA (South Carolina in particular, if I'm not mistaken, years ago) BECAUSE it got put up on wood stud walls in a hurricane zone no less (!!!)  - It cracked due to movement in the stud walls, water leaked in and it failed, "Oh look, this is a bad system!".

BS, it's a great system that hardly EVER fails if you know what you are doing. So yeah, you keep using it on wood studs...!

Yes, expansion and control joints are important like for any material, but less so for EIFS on solid masonry substrates. I can show you hundreds of large houses and even apartments in Central Europe - done some myself - (where EIFS is pretty common) without a single expansion joint or control joint, and there are no cracks in it. Why? Because it's put up on masonry substrate. That's why.

There are some wood frame houses being built over there nowdays, and have EIFS for the exterior cladding, and yes, THEY do need lots of joints. Such construction is rare in Europe for many reasons, but that's a discussion for another day.

Take a trip one day to Europe, and check it out.

Also, very few things are totally waterproof in building industry, but elastomeric coatings are far, far better than most exterior paints or simple stucco. Those are the coatings or finishes you want if you expect some substrate movement, but you cannot paint it over if you want to change the colour - you will have to reply a new coat of the elastomeric coating, and that is $$$.

BTW, weeps are only necessary at the bottom of the wall (and above heads of any openings) if you have insulation mounted on battens or thermal clips and you have an air space or vent space behind it. Most of the residential EIFS in Europe does not have the vent space and is not installed as a true vented rainscreen - insulation is fully attached to the substrate wall (ie., masonry) by using adhesives or special mortars. Some commercial / institutional buildings have rigid or semi-rigid insulation (usually mineral fibre due to fire regulations) attached directly to masonry, THEN a cement board is installed by means of thermal clips with an air space of a min. of 30mm in front of insulation. Cement board is then finished with base coat, mesh and finally a textured finish (which is usually elastomeric).

Hope this clarifies some of the issues.

I’ll give you a landscape tip, because that’s what I do.  A well placed wind break/hedge can minimize the horizontal wind driven rain...even if you can block 1/2 of it should take some of the stress off the other systems noted above.  

I’ve seen tons of these houses in Eastern Europe, self built with cheap and available materials at the time (during communism), they don’t have insulation and the glass is single pane (hopefully there are two windows to make it kind of double glazed) but these houses have serious moisture problems with or without rain. What kind of heating system do they use, coal?...I’ve seen plenty of people renovating these kinds of homes, they glue styrofoam to the exterior walls and finish that off with a layer of fibre glass and a coat of waterproof cement plaster of less than a cm or something and pastel paint, not a pretty sight, and they replace the windows with PVC double glazed ones, the cheap flat white ones.  But sometimes they forget to also insulate the roof properly and they’ll be boiling in summer and still heating the place like crazy in winter. And if there’s a basement insulate that too otherwise moisture will creep up behind the newly added styrofoam package and do serious damage there, nobody wants that.<br><br>But if you want to rebuild, it will most likely be with those orange hollow bricks, no, and again styrofoam on the exterior with the stucco. Same principle as renovation. You don’t need giant overhangs in that case but maybe think why all the houses in the area have those to begin with, they serve a certain and simple purpose and they serve it rather well, maybe exploit those overhangs and make them the key feature in a modern way. Those overhangs are also handy to keep your bicycle dry or the wood for the fireplace if you have one, to stand outside and smoke a cigarette and not get wet, to look for your house keys in a downpour etc. Those overhangs also prevent too much solar gain during summer on the facade and can be used by swallows to build nests under. 

Non Sequitur.

The Weinerberger is loadbearing masonry - not the same as our face brick. Yes, face brick veneer requires shelf angles as you note, but the Weinerberger does not. It simply sits on foundation walls and is "tied" at the top of the wall with a floor slab (either reinforced concrete or modular masonry/concrete slab - unique to Europe, never seen it here). There are several companies that make this brick, some also have mineral fibre insulation inserts in its air spaces; it can be had in many different thickness; from 100mm to 500mm - the thin ones are used for non-loadbearing interior walls...anything 150mm or more can be loadbearing. Weinerberger brick can be installed with either mortar joints or adhesives. They also have earthquake units where you shove a vertical rebar into it then fill it with concrete. There are also bond beam units or lintel units. 

Same thing applies to Ytong lightweight concrete blocks.

Both are used fairly commonly in Central Europe for housing and other buildings.

The insulation with dimples is by Dryvit, I think, which is not sold in Europe. They may also have rigid insulation with grooves cut in behind to channel water out.  It's a BS solution to water and delamination issues we have with EIFS in Canada, and the States. If the insulation was applied to a masonry substrate, as it is in Europe, with appropriate stucco/paint, you would not get water issues that we have here. It really comes down to either a rigid substrate (like masonry) or flexible one (like wood/steel studs). We just don't use it appropriately.

Same thing with Euros - they sometimes use asphalt roof shingles, then wonder why they fail within 4-5 years. "Did you vent the attic?", "No!". Well then, your shingles will turn into mush from the underside.

Like many things, one has to understand the material, and the construction method to avoid failures - in addition to having contractors who are qualified and trained properly.

There is a tonne of good videos on Youtube showing how to build with Weinerberger brick or Ytong lightweight blocks. If you have time, have a look at them. For what its worth, you don't need a vapour barrier nor an air barrier with either, and they go up very quickly. You can do large sloped roofs out of Ytong lightweight concrete slabs rather than wood rafters/joists.

When Dryvit first came out, they did not have a mechanically fastened system; they used adhesives. So they "fixed" it by using fasteners, huh?

Sealed system; "...such system not permitted under most Canadian arch insurance policies...". Do you know why? Too many failures? And why the failures?

Euro system is a "face sealed" system. You CAN get insulation with grooves or raised tracks, but most folks don't use it. The primary reason is that you will lose a little bit of thermal value in the insulation and the total wall assembly by having that air space behind it. If you really want the air space or a true rainscreen wall, what they do is, they attach the rigid insulation to the masonry wall (either fully adhered or with dabs of glue strategically located), then you do thermal brackets, then cementitious  board (with a 2-5cm of air space between the back of the board and the front of the insulation), then base coat, then reinforcing mesh, then final top coat which is usually plasticky and flexible up to a point. When you do this kind of a system, you must have control/expansion joints as cementitious boards flex under wind loads, and can crack the top coat.

Can't think of any commercial buildings that are built from concrete blocks nowdays - most are built with steel studs which can flex like crazy, and that will crack not just EIFS, but brick veneer as well. Hence, control joints.

I did some buildings out of concrete blocks many, many years ago (loadbearing  and non-loadbearing), but that fell out of favour due to economics and lack of speed compared to steel studs. Good brick layers are now more difficult to find as well.

"Chad,

Care to convert that to imperial units?"

1" = 25.4 millimeters

1 centimetre = 10 millimetres

1 metre  = 3.2804 feet

So, 300mm is roughly 12 inches

500mm is roughly 19.5 inches

There are many conversion apps you can download.

Here is a example of a Weinerberger Porotherm brick...they are loadbering, not face brick. If they "flexed" like face brick does you'd be in deep shit!

You can remain confused in that case...rolls eyes...!